Labor rationing, its main tasks

Working time structure

Methodology for recording working hours

Labor rationing- one of the main functions of production management, which includes establishing the time required to perform work by specific workers and establishing labor standards, that is, time standards, output standards, number standards, etc., established in accordance with the achieved level of technology, technology, organization of production and labor .

The most important tasks of labor standardization are:

• improving organization and productivity;
• reducing the labor intensity of products;
• increase in production volumes;
• effective use of the labor potential of employees, etc.

Labor rationing also makes it possible to determine the amount of individual remuneration for each employee, taking into account the quality of the work he performs and to assess the loss of working time and their impact on the performance of the employee’s main tasks.

Before moving on to studying the methodology for calculating time standards for performing a particular job, it is necessary to understand the structure of working time.

Work time- this is the time during which the employee must perform his job duties in accordance with the work schedule and his job description (the structure of working time is shown in the figure).

Working time structure

Working time consists of work time and break time.

Working hours- this is the part of the working time during which the employee performs certain work in accordance with the order of management or according to the job description.

3 components of operating time:

1) preparatory and final time;

2) operating time;

3) workplace servicing time.

Preparatory and final time- this is the time spent by a worker preparing to perform a given job and the actions associated with its completion. The peculiarity of the preparatory-final time is that its value does not depend on the volume of work, therefore, when the same work is being performed for a long time, the preparatory-final time per unit of work will be insignificant.

Operating time- this is the time spent directly on performing a given job. It is divided into main and auxiliary time.

Main time- This is the time spent by a worker on performing his main job. Moreover, this process can be performed directly by the worker or under his supervision (for example, time for lifting, moving and lowering a load; time for actively monitoring the progress of the instrumental process and adjusting it).

Auxiliary time- this is the time spent by a worker on activities that ensure the completion of the main job. It is repeated with a certain amount of work. The time spent on the worker’s movements necessary to perform operations and other similar work is also auxiliary.

Workplace service time- This is the time spent by a worker on caring for the workplace and maintaining it in a condition that ensures productive work during the shift.

Break times— time, which includes regulated (time for rest and personal needs) and unregulated breaks (violations of labor discipline, violations of the sequence of the production process, etc.).

You can organize the recording of working time using a methodology that is designed to calculate the labor intensity of work performed at enterprises, is based on the study of working time costs through observations and includes time-keeping observations and photographic observations (photography of working time).

For your information

The lunch break is not included in working hours.

Timing observations- this is the study of an operation by observing and studying the cost of working time to perform individual components of the operation, which are repeated many times during the work.

Note!

The purpose of timekeeping is to obtain initial data for developing time standards and establishing time standards for individual operations.

Photo surveillance (working time photography)- observation and measurements of all working time costs without exception during a shift in the order of the actual sequence of these costs. A photograph of working time allows you to accumulate the necessary material for standardizing preparatory and final time, time for servicing the workplace, and rest time.

Time tracking: methods and stages

Tracking working hours using a photo of the working day

Let's consider the features of using a photograph of a working day to standardize the work of the main production workers of industrial enterprises.

Stage 1. Determine the purpose of photo surveillance

The purpose of photo surveillance is to establish standards for preparatory and final time, time for servicing the workplace and time for rest and personal needs.

For your information

Photographs of working time are not used to standardize operational time - time-keeping observations are used for this.

Stage 2. Select the object of observation

It is important to choose the right employees when conducting observations, on the basis of which standards will be established and standards will be developed. The intensity of work varies among different employees due to their psychophysical characteristics, and the standard should provide for an average intensity of work.

Observations should be carried out on employees whose qualifications correspond to the type of work and who have work experience of at least 2 years.

Stage 3. Determine the number of observations

To ensure sufficient accuracy of the results, depending on the type of production, it is recommended to carry out from 5 (for single and small-scale) to 20 (for mass) photo observations, summarizing the results obtained.

Stage 4. We carry out photo surveillance

Carrying out photographic surveillance involves a detailed and consistent declaration of all operations performed by an employee in the workplace. Photographing is carried out from the moment the work shift begins, and the start time and end time of the observed operations are recorded. Recording can also be done using a video surveillance system.

To obtain results with a high degree of reliability, it is recommended to conduct observations on different performers.

Stage 5. Processing the results of the working time photograph

Processing the results of photographs of working hours involves analyzing the material, as well as entering the results of the observation into an observation sheet (Table 1).

Table 1

Observation sheet No. 1

No.		Current time		Duration in minutes	Index
		watch	minutes
	Preparation of tools and equipment.
	Cleaning the workplace at the end of the working day
	Time for natural needs

The observation sheet indicates all the actions of the performer and breaks in work in the order in which they actually occurred, while simultaneously recording the current end time of each type of time expenditure, which, in turn, is the beginning of the next type of expenditure. Each entry shows either what the performer did or what caused his inaction.

Paragraphs 1, 7, 23, 24, 25 reflect preparatory and final work, work to maintain the workplace, and time for personal needs. All other time costs relate to operational time. These points are needed to determine the ratio of these types of time to operational time.

After filling out columns 1-4 of the observation sheet, the duration of each element is calculated by subtracting the previous measurements from each subsequent measurement of the current time. The results are entered in column 5. Column 6 indicates the time expenditure index, that is, a characteristic of the type of working time expenditure in accordance with the classification (Table 2).

table 2

Indexation of working time costs

Index	Decoding
	Time (duration) of work
	Time (duration) of breaks
	Preparatory and final time
	Operating time
	Main time
	Auxiliary time
	Workplace service time
	Time to rest
	Time for natural needs
	Time for rest and natural needs
	Time of breaks due to reasons beyond the control of the worker
	Break times due to work-related reasons

Based on the results of observations, a summary of the elements of preparatory and final time, time for servicing the workplace and time for rest and personal needs is compiled (Table 3).

Table 3

Summary of elements of preparatory and final time (time for maintaining the workplace, time for rest and personal needs)

No.	Index	Name of working time costs	Observation sheet no.					Average value
			23.11.2015	25.11.2015	26.11.2015	08.12.2015	16.12.2015
			Duration, min
		Preparation of tools and equipment
		Cleaning the workplace
		Cleaning tools and equipment. Delivery to warehouse
		Time for natural needs (total per day)

Using a photograph of working time, the percentage of preparatory and final time (time for servicing the workplace and time for rest and personal needs) of operational time is determined.

Let us carry out calculations based on the fact that the working day is 8 hours:

• preparatory and final time - 0.11 of operational time:

45 min. / (8 hours - 30 minutes - 15 minutes - 15 minutes - 10 minutes);

• time for servicing the workplace - 0.037 of the operational time:

15 minutes. / (8 hours - 30 minutes - 15 minutes - 15 minutes - 10 minutes);

• time for personal needs - 0.024 of operational time:

10 min. / (8 hours - 30 min. - 15 min. - 15 min. - 10 min.

Working time recording using time-keeping observations

Stage 1. We analyze the list of work performed and divide the studied standardized types of work into their component elements - operations, elements of operations, techniques, sets of techniques, actions, etc.

Stage 2. Establishing precise boundaries (fixing points) for the operations being studied

Fixing points— these are the moments of the beginning and end of the execution of an operation (operation element). It is at these moments that time measurements begin and end.

Fixation points must be clearly identified by external signs (visible or audible).

Stage 3. Determine the number of time-lapse observations

The number of necessary observations depends on the serial production:

• mass - 8-12 observations;
• large-scale - 6-10 observations;
• serial - 5-8 observations;
• small-scale - 4-6 observations.

Stage 4. Determine the object of observation

To identify the best practices, frontline employees should be observed.

If it is necessary to establish time standards for work performed by several employees, then from among them several people are selected who have an average level of fulfillment of production standards for the group and work experience in their specialty of at least 2 years.

If there are 2-3 people in a group, it is enough to watch one; if there are 4-5 people - two; if there are 6-8 people, then three, etc.

Stage 5. Timing observations

They should be carried out every 50-60 minutes. after the start of work and 1.5-2 hours before the end of work. It is not advisable to take measurements on the first and last day of the work week.

Let us consider the procedure for conducting timing observations using the example of small-scale production with an average number of observations of 5.

The observer counts the results of measurements visually according to the indicators of the stopwatch hand and enters the results of the observations into a time map (Table 4).

Primary data is entered in the “hours:minutes:seconds” format. Later, when processing the observation results, they are converted into decimal format (person-hour; person-minute; person-sec.).

Table 4

Time card

No.

Name of the operation (operation element)

Results of timing observations (hour:min:sec)

Number of results taken into account

Defective measurements, their cause and duration

Average operation time (hour:min:sec)

Stability coefficient, K mouth

norm

fact

Operation: Dismantling sensor A-712.11

Unscrew the 4 bolts and open the compartment hatch

Disconnect the electrical connector cable from the sensor

Unscrew the 12 sensor mounting screws

Remove the sensor along with the rubber gasket

Install the plug where the sensor was removed

Wrap the sensor with plastic film

Close the compartment hatch

TOTAL average duration of the operation “Removal of sensor A-712.11”:

After all measurements are taken, a number of values ​​are obtained characterizing the duration of operations (elements of operations), which is usually called time series.

Stage 6. Analyze the quality of the results obtained

First, we identify and exclude erroneous (defective) measurements from further analysis.

For your information

Erroneous (defective) measurements are those measurements whose duration is much longer than the average duration of the operation or, conversely, much less than its value.

Secondly, we analyze the quality of the results obtained through the magnitude of fluctuations in values ​​- through the stability coefficient (K st), which shows the ratio of the maximum and minimum measurement results:

To mouth = T max / T min,

where T max is the maximum duration of execution of this element of the operation;

T min - the minimum duration of execution of this element of the operation.

By comparing the actual values ​​of the stability coefficients for each element of the operation with its standard value, the quality of the timing is determined:

if K mouth fact ≤ To mouth standards, observation was performed qualitatively;

if K mouth fact > By mouth norms, then from the series of observational results obtained it is necessary to exclude one or both extreme values ​​(maximum or minimum), provided that they were not repeated more than once.

Note!

The number of excluded values, including erroneous (defective) ones, cannot exceed 15%. If the number of exceptions is exceeded, observations should be made again.

After excluding one or two extreme observation values, it is necessary to re-calculate K mouth and compare it with the standard value. If these results show that the observations were performed poorly and K mouth. fact ≤ To mouth norms, observations must be repeated first, further exclusion of values ​​is impossible.

Standard values ​​of the stability coefficient are presented in table. 5.

Table 5

Standard values ​​of the stability coefficient depending on the serial production and duration of the operation

Duration of the studied element of the operation, seconds.	Standard values ​​of the stability coefficient
	during machine operation	during machine-manual work	when working manually
Mass production
From 6 sec. up to 15 sec.
Over 15 sec.
Large-scale production
From 6 sec. up to 15 sec.
Over 15 sec.
Mass production
Over 6 sec.
Small-scale production
Small-scale production

For the small-scale production we are analyzing with manual work, the standard value of Kst = 3, its calculated value does not exceed 1.9 (0:02:30 / 0:01:19).

Thus, timing observations make it possible to establish the average value for the operational time of work performed by production workers for the operation “dismantling the A-712.11 sensor” - 0:12:00, or 0.2 man-hours.

Stage 7. Process the results obtained

Based on the remaining observation results (except for erroneous ones), it is necessary to establish the average duration of the operation elements by adding up the recorded results and dividing them by the number of observations made.

The classification of working time is presented in table. 6.

Table 6

Classification of time

Time	Types of jobs
Preparatory and final time t pz	Receiving tools, preparing them for work at the beginning of the shift and handing them over at the end of the shift; preparation of documentation necessary to perform the operation; obtaining consumables and spare parts necessary to complete the operation. Preparatory and final time is determined based on photo surveillance data and is set as a percentage of operational time
The main execution time of the operation is t O	The list of works related to the section “Main time for performing work” is determined by the technology for performing the work. The main time for performing the operation is determined according to timing observations
Auxiliary operation time, t V	The time required for the worker to move to perform the operation. The auxiliary time for performing the operation is determined from photographic observations.
Workplace service time, t orm	Inspection; cleaning the workplace after work is completed. Workplace maintenance time is determined based on photo surveillance data and is set as a percentage of operational time
Time for rest and personal needs, t He	Time for rest and personal needs is determined based on photographic surveillance data and is set as a percentage of operational time. In addition, rest time is also provided in accordance with the nature of the work performed: performing work in cramped conditions; taking into account temperature when performing work; taking into account the explosive hazard of the environment when performing work; working posture; pace of work, etc.

We determine the norms for spending time on regulated breaks

Rest time should not be less than 10 minutes. per shift. In addition, all workers, regardless of the type of work, are allocated 10 minutes. for personal needs. Where public areas are located at a distance, the time for personal needs increases to 15 minutes. per shift.

Thus, without applying correction factors to take into account working conditions, time for rest and personal needs should not be less than 20 minutes. per shift.

The time for regulated breaks, allocated depending on working conditions, is determined as a percentage or in minutes for an 8-hour work shift.

For your information

With a shorter or longer work shift, the time for regulated breaks increases or decreases proportionally.

Rest time allocated for nervous tension. Nervous tension is caused by nervous stress, one of the psychophysiological elements of working conditions, and is caused by a high pace of work, the need for concentration and constant attention, lack of time to complete work, the need to ensure safe work, etc. (Table 7).

Table 7

Rest time allocated for nervous tension

Characteristics of work	Rest time per shift
		% of operational time
Medium precision work. The size of the discrimination object is 1.1-0.51 mm Work on scaffolds with fencing Work related to hearing strain (radio operators, telephone operators, etc.) Work in underground mines
High precision work. The size of the discrimination object is 0.5-0.31 mm Work with responsibility for material assets Driving work Work at low heights without fencing, or with fencing above molten metal, the red-hot hearth of metallurgical units Work on downloading slag, draining and pouring hot metal, marking, cutting hot metal in a rolling stream
Works of special precision. The size of the discrimination object is 0.3-0.15 mm Work at heights or on scaffolds without fencing, when the use of personal safety equipment is not taken into account by labor standards Work with responsibility for the safety of others, with the risk of injury
Works of the highest precision. The size of the discrimination object is less than 0.15 mm Work involving high personal risk

For an uncomfortable working position time is also allocated for rest (Table 8).

Table 8

Rest time allocated for a working position

Characteristics of the main working postures and movements in space	Rest time per shift
		% of operational time
Fixed, "sitting"
Standing, frequent bending and turning of the body
Standing with arms outstretched
Huddled in tight places, lying down, on your knees, squatting
Walking from 11 to 16 km per shift
Walking over 16 km per shift

Rest time allocated due to meteorological conditions. Meteorological conditions at work include:

• temperature (in °C);
• humidity (in%);
• air mobility (m/sec);
• infrared (thermal) radiation (cal/cm 2 × min.).

Rest time is allocated for work with elevated air temperatures (Table 9).

Table 9

Rest time depending on the air temperature in the work area

Air temperature, ºС	Rest time per shift
		% of operational time

When the relative humidity decreases to 20% and increases to more than 75%, the time for rest should be increased by 1.2 times; when humidity decreases to 10% and increases above 80% - 1.3 times.

During heavy physical work, the rest time allocated for elevated temperature increases by 4 times.

Those working in open work areas at low temperatures are provided with breaks to warm up. During this period, the employee naturally rests. Therefore, additional breaks are not advisable. It is recommended to allocate time for heating for those working in conditions that cause hypothermia.

Time to rest when working with hazardous substances. Harmful substances are substances that, when in contact with the human body in case of violation of safety requirements, can cause occupational injuries, occupational diseases or deviations in health, detected by modern methods both in the process of work and in the long-term life of the present and subsequent generations (GOST 12.1 .007-76).

Rest time allocated for lighting. There is no time for rest due to insufficient lighting, with the exception of work performed in complete darkness - in this case, 15-20 minutes are allocated for rest. per shift.

Rest time allocated to employees of mental activities with varying work intensity. With a 5-day work week and an 8-hour shift, the duration of the lunch break is 30-60 minutes, and it is recommended to set regulated breaks 2 hours from the start of the work shift and 2 hours after a lunch break lasting 5-10 minutes. each (Table 10).

During regulated breaks, in order to reduce neuro-emotional stress, fatigue of the visual and other analyzers, it is advisable to perform sets of physical exercises, including eye exercises.

	Break	Time spending	Duration
				% of operational time
Morning shift
	Regulated break	2 hours after the start of work
	Lunch break	4 hours after the start of work
	Regulated break	6 hours after the start of work
	Micropauses		40 sec.-3 min.
Evening shift
	Regulated break	After 1.5-2 hours from the start of work
	Lunch break	After 3.5-4 hours from the start of work
	Regulated break	6 hours after the start of work
	Micropauses	Individually as needed	40 sec.-3 min.
Night shift
	Meal break	After 2.5-3 hours from the start of work
	Regulated break. Alternate individual rest when replacing the resting person with an adjuster or another operator	Deep hours of the night
	Micropauses	Individually as needed. Every hour (one and a half) of work	40 sec.-3 min.

The organization of work and rest regimes when working with a PC is carried out in accordance with SanPiN 2.2.2/2.4.1340-03 “Hygienic requirements for personal electronic computers and work organization: sanitary and epidemiological rules and standards” depending on the type and category of work activities.

Types of work activities are divided into 3 groups:

• group A - work on reading information from the screen;
• group B - work on entering information;
• group B - creative work in dialogue mode with a personal computer.

When performing functions related to different types of work activity during a work shift, the main work with a PC should be taken to be that which takes up at least 50% of the time during a work shift or working day.

For types of work activities, 3 categories of severity and intensity of work with a PC are established, which are determined:

• for group A - according to the total number of characters read per work shift, but not more than 60,000 characters per shift;
• for group B - according to the total number of characters read or entered per work shift, but not more than 40,000 characters per shift;
• for group B - based on the total time of direct work with a PC per work shift, but not more than 6 hours per shift.

Table 11

Total time of regulated breaks depending on the duration of work, type and category of work activity with a PC

	Load level per shift when working with a PC			Total break time
	group A, number of characters	group B, number of characters	group B, h		% of operational time

For your information

When working with a PC on the night shift (from 10 p.m. to 6 a.m.), regardless of the category and type of work activity, the duration of regulated breaks should be increased by 30%.

In general operating mode, the following regulations should be adhered to: at 120 min. 10 minutes of work are provided. break for rest and personal needs.

Calculation of indicators of standard time standards

Indicators of standard time standards are calculated using the following formula:

N in = t pz + t o + t in + t orm + t he + t y,

where N in is the time standard;

t pz - preparatory-final time;

t o is the main time for performing the operation;

t c - auxiliary time for performing work;

t orm - workplace servicing time;

t he is time for rest and personal needs;

t y is the time for rest allocated depending on working conditions.

Preparatory and final time, time for servicing the workplace and time for rest and personal needs are determined according to the photograph of working time as a percentage of operational time.

Rest time allocated depending on working conditions can be determined as a percentage of operational time:

t y = t op × K he,

Where t op - operational time for completing work ( t op = t o + t V);

K is a coefficient that takes into account the time for rest allocated depending on working conditions.

Based on the results of the research, indicators of the labor intensity of each operation within the work are determined. In this case, the total coefficient taking into account the conditions of work (∑K ur), which is calculated using the following formula, is applied to the results obtained:

∑K control = K 1 + K 2 + K 3 + . . . + K n,

where K 1, K 2, K 3, ..., K n are coefficients for taking into account the conditions of work.

Let us apply coefficients taking into account the conditions of work. Then the formula for calculating the time norm will take the following form:

N in = t pz + t o + t orm + t he + ( t op × ∑K control).

Example

Let us calculate the time standard for the operation “dismantling unit A-712.11”:

• operational time - 12 minutes. (0.2 person-hour), established by conducting time-lapse observations;
• preparatory and final time - 0.11 of the operational time, established by conducting photo observations; 0.11 × 0.2 = 0.022 person-hour;
• time for servicing the workplace - 0.037 of the operational time, established by conducting photographic observations; 0.037 × 0.2 = 0.0074 person-hour;
• time for rest and personal needs - 0.024 of operational time, established by conducting photo observations; 0.024 × 0.2 = 0.0048 person-hours

Now we will apply increasing coefficients to take into account working conditions.

The work of dismantling the A-712.11 unit involves:

• work with responsibility for material assets (from the section “Rest time allocated for nervous tension”), which is 2% of operational time;
• work standing with arms extended upward (from the section “Rest time allocated for working position”) - 2.5% of operating time;
• work at a temperature of 25 ºС (from the section “Rest time depending on the air temperature in the work area”) - 1% of the operating time.

The total factor taking into account working conditions is:

0,02 + 0,025 + 0,01 = 0,055.

Thus, the standard time for dismantling the A-712.11 unit will be:

0.022 + 0.2 + 0.0074 + 0.0048 + (0.2 × 0.055) = 0.25 person-hour, which is approximately 15 minutes.

Thus, the operational time for dismantling work spent by the production worker and associated with the direct implementation of dismantling work is 12 minutes, and the remaining 3 minutes. distributed among work site maintenance, preparatory and final work, rest time, personal needs, etc.

conclusions

Labor resource accounting is mandatory, but impossible without a labor standardization system.

Using the considered methodology for accounting for working time costs, it is possible to determine reasonable and, most importantly, labor standards that are closest to reality.

In conclusion, let us summarize the basic principles of labor regulation:

• proper organization of work and rest schedules for enterprise employees;
• mandatory classification of working time with a clear definition of the list of works belonging to each group;
• determination of the type of enterprise depending on the serial production of products;
• determination of working time groups that will be standardized using photo and timing observations;
• determination of a group of specialists who will be monitored;
• conducting observations with a clear recording of their results minute by minute in the appropriate document forms (you can use those presented in the article or develop your own forms, securing them in a regulatory act of the enterprise);
• analysis of results with an emphasis on average values ​​of indicators.

A. N. Dubonosova,
Deputy Head of PEO

Production rate. Technical time standard. Auxiliary time. Basic (technological) time.

Technical standardization establishes a time standard, i.e., the time required to perform a given operation under certain production conditions.

According to the time standard for an operation, the time spent on the entire program for producing parts is calculated, the required number of workers, machines, the amount of electricity is determined, the needs for grinding wheels are determined, etc.

In accordance with time standards, a production plan for the site, workshop, and plant as a whole is drawn up. Workers are paid based on time spent. The time spent on an operation characterizes labor productivity. The less time spent on one operation, the more parts will be processed per hour or shift, i.e., the higher labor productivity.

The production rate is understood as the number of operations (volume of work) that a worker can perform per unit of time (per shift, per hour). Knowing the duration of the shift (420 minutes, with a 7-hour working day or 480 minutes, with an 8-hour working day) and the standard time for one operation (T), determine the production rate (420: T or 480: T).

The time standard is not a constant value, since with an increase in labor productivity the time standard decreases and the production rate increases.

When determining the norm, the best organization of labor and maintenance of the workplace is provided for, i.e., the norm should not include loss of time due to organizational problems in servicing the workplace.

The worker's qualifications must correspond to the work performed; The machine operator must not perform the kind of work that auxiliary workers are required to do.

The norm should also not include wasting time on correcting defects or manufacturing parts to replace rejected ones.

When calculating the time standard, the actual cutting conditions for a given operation, normal processing allowances, and the use of a specific tool and device must be taken into account.

The technical time standard for an operation consists of two main parts: the piece time standard and the preparatory-final time standard.

The standard piece time refers to the time spent processing a part on a machine.

The norm of preparatory-final time is understood as the time spent on familiarization with the drawing or operational sketch and the technological process of performing the operation, on setting up the machine, installing and removing tools (grinding wheels) and devices, as well as on performing all the techniques associated with completing a given task. work - handing over finished products to the inspector, handing over tools to the tool store, etc.

Preparatory and final time is spent once for the entire batch of simultaneously processed parts. In mass production, the same operations are performed on machines. Therefore, the worker should not change the device, tools, or familiarize himself with the drawings and technological maps for the manufacture of the part multiple times. He does this once before performing this operation.

Consequently, in mass production, the preparatory and final time is not included in the technical norm. The processing time for a batch of parts in mass production is determined by the formula

T desks =T pcs n +T pz,

where T desks is the standard time for a batch, min; T piece - piece time, min;

n - number of parts in the batch, pcs.; T pz - preparatory and final time, min. From this formula you can determine the time to manufacture one part if you divide the right and left parts by the number of parts in the batch

where T pcs is the norm of piece-calculation time, i.e., the time for the operation, taking into account the preparatory and final time. The value of T pz can be taken from standardization reference books.

From the formula it is clear that the larger the batch of parts processed on the machine, the smaller the fraction and, therefore, the smaller the T piece.

The standard piece time includes the following values:

T pcs =T o +T in +T obsl + T from,

where T o - main (technological) time, min; T in - auxiliary time, min; T service - workplace service time, min; T from - time of breaks for rest and natural needs, min.

The main (technological) time T o is the time during which the shape and dimensions of the workpiece change.

The main time can be:

a) machine, if the change in shape and size is carried out on a machine without the direct physical influence of the worker, for example, grinding on a machine with automatic feed of the grinding head;

b) machine-manual, if the change in shape and size is carried out on equipment with the direct participation of a worker, for example, grinding on a machine with manual feed of the grinding head;

c) manual, if changing the shape and dimensions of the part is done manually by a worker, for example, metalwork - scraping, filing the surface, etc.

The main machine time when grinding using the multiple passes method is calculated using the formula

In these formulas the following designations are adopted: l - stroke length of the work table when grinding a given part, mm; q - allowance per side, mm; n is the number of revolutions of the part per minute; s pr - longitudinal feed per revolution of the part, mm/rev; s pp - transverse feed per table stroke (depth of cut), mm/stroke or mm/min, for plunge-cut grinding;

K - coefficient taking into account the time to produce a spark, is taken from 1.1 to 1.5. The length of the working stroke l when grinding with longitudinal feed is determined by the formula l=l d -(1-2m)*B, where l d is the length of the grinding surface in the direction of the longitudinal feed, mm; m is the overtravel of the wheel beyond the surface being ground in fractions of the wheel height;

B - height of the circle, mm. If you need to determine the number of double table strokes per minute n dx, then you need to find the minute longitudinal feed and the length of the working stroke, and then use the formula

where s pr is the longitudinal feed per revolution of the part; n d - number of revolutions of the part. In turn, between the reverse feed s in mm/rev and the feed in fractions of the circle height s d for one revolution of the part there is a relationship s in = s d B.

Substituting the indicated values ​​into the formula, for s m we obtain:

s m =s pr *n d =s d *B*n d mm/min.

When determining the number of revolutions of a part, when its diameter and rotation speed are known, use the formula

where v d is the rotation speed of the part, m/min;

d d - part diameter, mm.

Auxiliary time T in is the time spent on various techniques used in performing the main work and repeated with each workpiece, i.e., feeding the workpiece to the machine, installing, aligning and clamping the workpiece, unclamping and removing the part, controlling the machine, control measurements of the part.

Auxiliary time is determined by timing. There are reference books that indicate auxiliary time for various cases of processing parts.

According to the Experimental Research Institute of Metal-Cutting Machine Tools (ENIMS), auxiliary time is distributed approximately as follows:

For supplying blanks to the machine 5-10%

For installation, fastening, unfastening and removal of parts 15-25%

For machine control, including manual supply (retraction) of the grinding headstock 35-50%

For measuring a part on a machine 20-40%

Workplace maintenance time T serv is the time that a worker spends on caring for his workplace throughout the entire shift. It includes the time for changing the tool (grinding wheel), which, according to ENIMS, is 5-7% of the total amount of time spent on adjusting and adjusting the machine during operation, and for dressing the grinding wheel with diamond or diamond substitutes, which is 5-10% of the total amount of working time spent on removing chips during work, on arranging and cleaning cutting and auxiliary tools at the beginning and end of a shift, on lubrication and cleaning of the machine.

To reduce maintenance time, it is essential to reduce the time for editing, achieved by using diamond mandrels, pencils, plates, rollers, disks, automatic devices for sending commands for editing and automation of editing (automatic adjusters).

Time for rest and breaks from work for natural needs is determined for the entire shift. The time for servicing the workplace and for natural needs is set as a percentage of operational time, i.e., the sum of T o + T c.

Based on a study of the work experience of grinders, it has been established that from 30 to 75% of the total working time is spent on the main time. The rest consists of auxiliary time, time for maintaining the workplace, natural needs and preparatory and final time.

With a decrease in T in, T obs, T from, T pz, T pcs and T pcs decreases, labor productivity increases.

Having calculated all the components of the time standards T o, T in, T obsl, T from, T pz and knowing the batch of simultaneously processed parts, T pieces are determined.

Knowing the T pcs and the number of hours of work per shift, you can set the production rate per shift:

where 480 is the number of minutes in a shift for an 8-hour working day.

From these formulas it is clear that the lower the time standard T pcs, the greater the output per hour and shift. With well-organized work, workers fulfill and exceed production standards, which leads to the fulfillment and exceeding of the production plan and an increase in labor productivity.

In addition to the design and technical time standards, experimental statistical time standards are used in individual production. Such standards are obtained as a result of mathematical processing of the actual time spent on performing the entire operation. These time standards do not take into account all the possibilities for increasing labor productivity, and therefore it is not recommended to use them.

Working time concept

Working time is measured in different ways. This could be a shift, a day, a week, a month or a year. This time is a measure of labor evaluation. Shift lengths vary across countries and across different types of work, working conditions and occupations.

The purpose of classifying working time costs

This classification makes it possible to establish optimal amounts of working time, identify the proportion of wasted time, and determine directions for increasing labor productivity at the enterprise.

Classification of working time costs

Working time costs are divided into separate categories and types. When compiling the classification, the proportions and sizes of the constituent elements of the entire working time are taken into account.

Working time is generally divided into:

• time spent on completing a production task (working time);
• time spent on a break from work.

In turn, working time is divided into:

• preparatory and final time;
• operational time;
• workplace service time.

Preparatory-final time involves spending time preparing for the start of the labor process and for the end of such a process. For example, a worker performs the quota of a certain task (producing products) using some equipment. Before starting work, the worker needs to prepare the workplace (starting up equipment, warming up, etc.). At the end of the work task, the worker must put the equipment in proper condition (remove, lubricate, wipe, etc.).

Note 1

It is worth noting that the length of time spent on preparation and completion of work does not depend on the standards for completing the task. For example, one hundred units need to be produced or three hundred units - the time spent on preparation and completion of work will be invariably constant. In this regard, the highest possible standards are being developed that will justify the costs of preparing and completing the work.

Operating time is the time directly spent on completing a production task (compliance with standards).

In turn, operational time is divided into:

• main time;
• auxiliary time.

Basic time is the time during which the actual production of the object of labor occurs.

Auxiliary time is time that ensures quality time spent on primary time. This could be the installation or replacement of some parts in the equipment, stopping most of the time to control the quality of manufactured products, etc.

Workplace maintenance time involves spending time on maintaining the workplace in proper order.

In turn, such time is divided into:

• Maintenance;
• organizational services.

Worksite maintenance ensures the smooth operation of equipment and tools.

Organizational services include maintenance of the workplace (layout, layout, etc.).

In addition to these types of working time costs, there may be other types.

Work time that is not provided for by the production task. In this case we mean random and unforeseen tasks. For example, during a power outage, it is necessary to spend time starting the generator.

Also, time can be spent on non-productive work, that is, on tasks that are in no way related to production requirements.

The time of breaks in work can be regulated or unregulated.

Unscheduled breaks can occur for both production and non-production reasons.

The study of working time costs is based on their classification.

Such a classification is necessary to establish the structure of working time and assess the feasibility of each of its elements.

Analysis of working time costs according to the accepted classification allows us to identify the workload and nature of the worker’s employment in the production process, the use of equipment, the content and nature of individual operations, losses and unproductive costs of working time.

Differentiated classifications of working time costs have been adopted as unified ones that meet the requirements of all sectors of the national economy. performer And time of equipment use, containing the most fractional division of time spent by category and type.

In cases where it is practically impossible to single out for study separate fractional categories and types of time spent when performing some work, more enlarged categories and types of time spent are studied.

To analyze and rationalize the labor process and develop labor standards, it is necessary to carefully study the working hours of the work performer and the time of use of equipment. The basis for such a study is the appropriate classification of these costs into categories. It creates a certain uniformity, which allows the use of uniform methods for studying and analyzing costs or losses of working time, uniform regulatory materials and methods of labor standardization. Differentiated classifications of contractor's working time costs have been adopted as satisfying the requirements of all industries.

Working time is the legally established full duration of the working day, during which the contractor must perform the work assigned to him (with the exception of the lunch break).

The working time of a shift for a performer of work is divided into the time of work of the performer (during which the worker performs one or another work provided for or not provided for by the production task) and the time of breaks in the work of the performer (during which the worker does not work). The structure of a worker's working time is shown in Figure 2.1.

The work time to complete a production task consists of the following categories of working time spent by the work performer.

Preparatory and final time (T PZ ) - this is the time spent by a worker preparing to perform a given job and the actions associated with its completion. This type of working time costs includes the time of: obtaining a production task, tools, devices and technological documentation; familiarization with the work, technological documentation, drawing; receiving instructions on how to perform the work; setting up equipment for the appropriate operating mode; trial processing of a part on a machine; removal of fixtures, tools, delivery of finished products to quality control department; delivery of technological documentation and drawings. The peculiarity of this category of time expenditure is that its value does not depend on the amount of work performed on this task, i.e. These are one-time costs for a batch of manufactured products. Therefore, in large-scale and mass production, per unit of production it is insignificant in magnitude and is usually not taken into account when establishing standards.

Operating time (T OP ) . This is the time spent directly on performing a given job (operation), repeated with each unit or a certain volume of product or work. It is divided into main and auxiliary time during machine work.

Main time(T ABOUT). This is the time spent by the worker on actions to qualitatively and quantitatively change the subject of labor, its condition and position in space.

Auxiliary time(T IN). This is the time spent by a worker on activities that ensure the completion of a given job.

It is repeated either with each processed unit of production, or with a certain volume of it. Auxiliary time includes time for: loading equipment with raw materials and semi-finished products; unloading and picking up finished products; installation and fastening of parts; detaching and removing parts; moving the subject of labor within the work area; equipment management; movement of individual equipment mechanisms; rearrangement of the working tool, if this is repeated with each unit of production; control over the quality of manufactured products; movements (transitions) of the worker necessary to perform operations, and other similar work.

Workplace service time (T OBS ) . This is the time spent by a worker maintaining the work station and maintaining it in a condition that allows for productive work during the shift. In machine and automated production processes, this time is divided into maintenance time and organizational maintenance time.

Maintenance time(T THOSE). This is the time spent maintaining the work station, equipment and tools needed to complete a specific task. This includes time spent on sharpening and replacing worn-out tools, adjusting and fine-tuning equipment during operation, removing production waste, inspecting, testing, cleaning, washing, lubricating equipment, etc.

Organizational service time(T ORG). This is the time spent by a worker maintaining the workplace in working order during a shift. It does not depend on the characteristics of a particular operation and includes the time spent on receiving and turning over a shift; laying out at the beginning and cleaning at the end of the change of tools, documentation and other materials and items necessary for work; movement of containers with blanks or finished products within the workplace, etc.

Time spent by workers observing equipment operation . In mechanized and automated production, this time has a significant share. It can be active or passive.

Time of active monitoring of equipment operation(T AN). This is the time during which the worker closely monitors the operation of the equipment, the progress of the technological process, and compliance with the specified parameters in order to ensure the required product quality and serviceability of the equipment. During this time, the worker does not perform physical work, but his presence at the workplace is necessary.

Time of passive observation of equipment operation(T Mon). This is the time during which there is no need for constant monitoring of the operation of the equipment or technological process, but the worker carries it out due to the lack of other work. The time of passive observation of equipment operation should be the subject of particularly careful study, since its reduction or use to perform other necessary work is a significant reserve for increasing labor productivity.

Working time not provided for by the production task (T NZ ) . This is the time spent by an employee performing random and unproductive work. It is divided like this.

Occasional work time(T SR). This is the time spent performing work not provided for by the production task, but caused by production necessity (for example, transporting finished products, performed instead of an auxiliary worker).

Unproductive work time(T HP). This is the time spent on performing work that is not provided for by the production task and is not caused by production necessity (for example, the time to correct a manufacturing defect).

Performing random and unproductive work does not provide an increase in production or an improvement in its quality and is not included in the standard piece time. These costs should be the subject of special attention, since their reduction is a reserve for increasing labor productivity.

Time of breaks from work is divided as follows.

Time of regulated breaks in work. Includes time of breaks in work due to technology and organization of the production process ( T PT), for example, a break in the work of a crane operator while workers are slinging a lifted load. This category also includes time for rest and personal needs contractor ( T OTD).

Unregulated breaks from work. This is the time of interruptions in work caused by a disruption in the normal flow of the production process. It includes the time of interruptions caused by deficiencies in the organization of production ( T PNT): untimely delivery of materials and raw materials to the workplace, equipment malfunction, power outages, etc., and time of breaks in work caused by violation of labor discipline ( T HDPE): being late for work, absences from the workplace, leaving work early, etc.

When analyzing the costs of working time in order to identify and subsequently eliminate losses of working time and their causes, all working time of the performer is divided into productive costs and lost working time. The first group includes the time of work to complete a production task and the time of regulated breaks. These costs are subject to rationing and are included in the structure of the time norm. Lost working time includes time spent performing unproductive work and time spent on unregulated breaks. These costs are the object of analysis with the aim of eliminating them or reducing them as much as possible.

Posted On 03/26/2018

Yu.I.Rebrin
Organization and production planning
Taganrog: TRTU Publishing House, 2006

Brief theoretical part

Standardized time is the time required to complete an operation or work.

Irregular time occurs due to various technical and organizational problems (not included in the standard time).

Standardized time is divided into:

– for preparatory and final (tp.z.);

– basic (to.s.);

– auxiliary (tvs.);

– organizational maintenance of the workplace (to.o.);

– technical maintenance of the workplace (t.o.);

– rest and natural needs (t.n.).

The structure of standardized time (performing an operation, work) (tshk, tshk) is shown in Fig. 6.

Fig.6. Structure of piece-calculation time

Preparatory and final time tп.з. – time spent by a worker performing the following work:

– receipt and familiarization with technical documentation (drawings, specifications, technological process);

– preparation of equipment (adjustment, readjustment), tools, devices, measuring instruments (selection and receipt);

– actions related to the end of processing.

Preparatory and final time is spent on the entire batch of parts (products) and does not depend on its size.

In mass production tп.з. no, since parts (products) are processed continuously throughout the entire production period.

The main time toc is the time during which the technological process is directly carried out (the shape, dimensions, physical and chemical properties of the part or product change).

to.s. May be:

– manual;

– machine-manual;

– machine-automatic;

– hardware.

Auxiliary time tв., spent on actions that directly create the opportunity to perform work elements related to the main time:

– installation and removal of a part (product);

– securing and detaching a part (product);

– measurements;

– supply and removal of tools;

– turning equipment on and off.

In conditions of mass and serial production, when group processing methods or instrumental technological processes (thermal, galvanic, etc.) are used, the main and auxiliary time is set for the batch, depending on the throughput of the equipment. The time for one part can be determined using the formulas

where toc.par., tv.steam. – respectively, the main and auxiliary time for a batch of parts (products);

n – number of parts (products) in a batch (in a cassette, pallet, etc.).

Time for organizational maintenance of the workplace tо.о. – time for cleaning waste and the workplace, receiving and handing over tools, measuring instruments, devices, accepting the workplace from the shift, etc., spent during the shift.

Workplace maintenance time tt.o.:

– time for lubrication, adjustments, changing dull tools, etc. during the shift.

Time for rest and natural (personal) needs ten. installed to maintain the worker’s performance during the shift.

In accordance with the above classification of working time costs, its structure is established (Fig. 6.) and a technically justified standard of time is calculated.

Standard piece time tpcs. – used in mass production conditions:

.

Time to.to. and ten. usually expressed as a percentage of the operating time top. Then

tpcs. = top (1 + Photo. + Ken.),

where is Koto. and Ken. – shares of time (from top), respectively, for organizational and technical services and rest and natural needs.

Norm of piece-calculation time tshk. – used in mass production, where the proportion of preparatory and final time is high:

;

where n is the number of parts (products) in the batch.

Production rate - the amount of products that must be produced by a worker per unit of time (hour, shift, etc.)

where Nв – production rate, units;

Fr.v. – working time fund for a certain period of time (shift, month, year), in minutes, hours.

Problem No. 7

According to the initial data of table. 7 define:

– the norm of piece-calculation time for processing a part;

– replacement rate of production of parts.

Table 7

Labor standardization methods

The concept of labor rationing

Standards labor standards include initial values ​​that are used when calculating the duration of the corresponding work under certain organizational and technical production conditions. For example, time standards are able to establish the necessary time spent on performing individual elements of a technology or work process. The object of development of time standards is represented by elements of the labor and technological process, including types and categories of working time costs.

Labor standardization methods

Labor standardization methods are ways of researching and designing labor processes in order to set cost and labor standards. There are two main methods of labor standardization: summary and analytical

The summary method includes the experimental, experimental-statistical and comparison methods. Summary methods are characterized by setting time standards for the operation as a whole. In this case, there is no analysis of the labor process, the rationality of performing techniques and the time spent on their implementation are not considered. Here, the determination of standards is based on the use of statistical accounting data on actual working hours.

The summary method involves setting labor standards in the following ways: the experimental or expert method, the experimental statistical method, the method of comparison or analogy.

Analytical methods of labor standardization

Analytical methods of labor standardization include calculation, research, and mathematical and statistical methods.

Analytical methods divide the labor process into elements.

At the same time, the design of a rational mode of operation of equipment and working methods of workers is carried out, standards are determined in accordance with the elements of the labor process, taking into account the specifics of the corresponding workplaces and production units. Analytical methods establish a standard for each operation.

Research Methods

Research methods for rationing labor are determined on the basis of studying the costs of working time that are necessary to perform a labor operation. These studies are carried out by time-based observations, before conducting which all shortcomings in the organization of workplaces are eliminated. Next, the standardized labor operation is divided into elements, with the definition of fixation of different points. Specialists establish the composition and sequence of execution of the elements of a labor operation, determining the duration of the designed elements of the operation using timing.

At the end of the calculations, labor standards and elements of the operation are determined. After the operation as a whole, experimental verification is carried out.

Calculation methods

Calculated methods of labor standardization establish labor standards based on initially developed time standards and equipment operating modes. In this case, the labor operation is divided into several stages, including techniques and labor movements. Next, the rational content of the elements of operations is established, as well as the sequence of their implementation.

Subsequently, the composition and structure of the operation as a whole is designed. Time standards for elements of an operation can be determined on the basis of time standards or calculated in accordance with standards for equipment operating modes. The calculation is made both according to time standards and according to calculation formulas that establish the dependence of the execution time of individual elements of an operation or the entire operation as a whole on factors affecting the execution time.

Mathematical-statistical method

Mathematical and statistical methods of labor standardization involve establishing a statistical dependence of the time standard on factors that influence the labor intensity of the work being standardized.

Using this method may require computer equipment and certain software.

Calculation of the standard time for performing a service

Mathematical and statistical methods of labor standardization also require suitably trained standardizers. If all these requirements are met, the method will be effective.

Examples of problem solving

Classification of working time costs

Working time for the performer of work is divided into working hours (during which the worker performs this or that work provided for or not provided for by the production task) and break time at work (during which the labor process is not carried out for various reasons). The structure of a worker's working time is presented in Figure 6.1.

So, working hours is divided into two types of costs: production task completion time (TPROIZ) And work time not provided for by the production task (TNEPROIZ) - time spent on performing operations that are not typical for a given employee, which can be eliminated.

Production task completion time includes preparatory and final, operational and workplace maintenance time.

Preparatory and final time (TPT)- this is the time spent preparing oneself and one’s workplace to complete a production task, as well as all actions to complete it. This type of working time costs includes the time of receiving a production task, tools, devices and technological documentation, familiarization with the work, receiving instructions on the procedure for carrying out the work, setting up equipment for the appropriate operating mode, removing devices, tools, handing over finished products to the quality control department, etc. . Since the peculiarity of this category of time expenditure is the fact that its value does not depend on the amount of work performed on a given task, then in large-scale and mass production per unit of product this time is insignificant in size and is usually not taken into account when establishing standards.

Operational time (TOPER)– this is the time during which the worker completes the task (changes the properties of the object of labor); is repeated with each unit or a certain volume of production or work. During machine work it is divided into main (technological) and auxiliary.

Basic (technological) time (TOSN),- this is the time spent directly on a quantitative and (or) qualitative change in the subject of labor, its condition and position in space.

During auxiliary time(TVSP) actions necessary to carry out the main work are performed.

Time, production and service standards: what's the difference?

It is repeated either with each processed unit of production, or with a certain volume of it. Auxiliary time includes time for loading equipment with raw materials and semi-finished products, unloading and removing finished products, installing and securing parts, moving objects of labor within the work area, operating equipment, monitoring the quality of manufactured products, etc.

The time spent on caring for the workplace and maintaining equipment, tools and devices in working order during the shift is classified as workplace service time (TOBSL). In machine and automated processes it includes technical and organizational maintenance time for the workplace.

By the time of workplace maintenance (TOBSL.TEKHN) refers to the time spent servicing the workplace in connection with the performance of a given operation or specific work (replacing a dull tool, adjusting and fine-tuning equipment during work, removing production waste, inspecting, cleaning, washing, lubricating equipment, etc.).

Organizational service time (TOBSL.ORG) – this is the time spent by a worker on maintaining the workplace in working condition during a shift. It does not depend on the characteristics of a particular operation and includes the time spent on receiving and handing over a shift, laying out at the beginning and cleaning at the end of the shift tools, documentation and other necessary for work objects and materials, etc.

In some industries (coal, metallurgical, food, etc.), the time spent on servicing the workplace is not allocated, but refers to the preparatory and final time.

Working time not provided for by the production task, - time spent by an employee performing random and unproductive work. Performing unproductive and random work does not provide an increase in production or improvement in its quality and is not included in the standard piece time. These costs should be the subject of special attention, since their reduction is a reserve for increasing labor productivity.

Random work time (TSL.RAB)- this is the time spent on performing work that is not provided for by the production task, but caused by production necessity (for example, transporting finished products, performed instead of an auxiliary worker, going for work orders, technical documentation, raw materials, blanks, tools, searching for a foreman, service technician, tools; not performing auxiliary and repair work provided for in the task, etc.).

Figure 6.1 – Classification of contractor’s working time costs

Non-productive work time (TNEPR.WORK)- this is the time spent on performing work that is not provided for by the production task and is not caused by production necessity (for example, manufacturing and correcting manufacturing defects, removing excess allowance from a workpiece, etc.)).

In addition to the above, depending on the nature of the employee’s participation in the production operation, operating time can be divided into:

- manual work time(without the use of machines and mechanisms);

- machine-manual work time performed by machines with the direct participation of an employee or by an employee using manual mechanisms;

- observation time the operation of equipment (automated and instrumental work);

- transition time(for example, from one machine to another during multi-machine service).

Observation time, as noted, it is typical for automated and hardware-based production.

It can be active or passive. Active surveillance time equipment operation is the time during which the worker carefully monitors the operation of the equipment, the progress of the technological process, and compliance with specified parameters in order to ensure the required product quality and serviceability of the equipment. During this time, the worker does not perform physical work, but his presence at the workplace is necessary. Passive observation time equipment operation is the time during which there is no need for constant monitoring of the operation of the equipment or the technological process, but the worker carries it out due to the lack of other work. The time of passive observation of equipment operation should be the subject of particularly careful study, since its reduction or use to perform other necessary work is a significant reserve for increasing labor productivity.

Considering the structure of working time costs in machine, automated, hardware processes in operating time, it is also advisable to distinguish overlapping and non-overlapping time.

Overlapping time- the time the worker performs those elements of work that are carried out simultaneously with the machine or automatic operation of the equipment. The overlapped time can be primary (active observation) and auxiliary time, as well as time related to other types of working time expenditure. Non-overlapping time - time for performing auxiliary work and work on servicing workplaces when the equipment is stopped. Increasing the overlapped time can also serve as a reserve for productivity growth.

As noted, working time includes break time. There are regulated and unregulated breaks.

Time of regulated breaks (TREGL.PER) work includes:

- time of breaks in work due to technology and organization of the production process (for example, the time a driver takes a break while workers are slinging a lifted load) - their elimination is practically impossible or economically impractical;

- time for breaks for rest and personal needs, associated with the need to prevent fatigue and maintain normal performance of the employee, as well as necessary for personal hygiene.

Time of unregulated breaks in work (TNEREGL.PER)– this is the time of breaks caused by a disruption in the normal flow of the production process or labor discipline. It includes:

- interruptions due to disruption of the normal course of the production process may be caused by organizational problems (lack of work, raw materials, supplies, incomplete parts and workpieces, waiting for vehicles and auxiliary workers, waiting for acceptance or control of finished products, etc.) and technical reasons (waiting for equipment repair, replacement tools, lack of electricity, gas, steam, water, etc.).

Sometimes these types of unregulated breaks are called breaks for organizational and technical reasons;

- breaks caused by violation of labor discipline, may be associated with being late for work or leaving work early, unauthorized absences from the workplace, extraneous conversations, or activities not related to work. These also include excessive (compared to the established regime and standards) rest time for workers.

When analyzing the costs of working time in order to identify and subsequently eliminate losses of working time and their causes, all working time of the performer is divided into productive costs and lost working time. The first group includes the time of work to complete a production task and the time of regulated breaks. These costs are subject to rationing and are included in the structure of the time norm. Lost working time includes time spent performing unproductive work and time spent on unregulated breaks. These costs are the object of analysis with the aim of eliminating them or reducing them as much as possible.

SEE MORE:

Calculation of technical time standards for welding operations

Standard time

The most common form of measuring labor costs is the time standard, in which costs are measured in standardized man-hours (standard hours).

(For example, the norm for the production of product “A” is 16 man-hours, the norm for the production of 1 m of fabric “K” is 38 man-hours.)

Time standard (Nvr.) is the reasonable time spent on performing a unit of work (one production operation, one part, product of one type of service, etc.) by one or a group of workers of a specified number and qualifications in specific production conditions.

The time standard is generally calculated using the following formula:

N time = t pz + t op + t about + t exc + t pt,

where N time is the standard time per unit of production

t pz – preparatory-final time

t op – operational time

t about – time for servicing working hours

t exc – time for rest and personal needs

t pt – time of breaks due to technology and organization of the production process.

Time standards have many varieties and occupy a central place in the calculation of labor standards, since on their basis other types of standards are determined.

Time standards are used both to standardize the work of workers of any profession engaged in performing various types of work during a shift, and to standardize the work of specialists of different levels and areas.

Time standards are one of the types of labor standards that help ensure the effective operation of organizations.

Production rate

The production rate is the amount of work in pieces, meters, tons (other natural units), which must be performed by one worker or group of workers of the established number and qualifications per unit of time (hour, shift, month) in specific organizational and technical conditions.

The production rate in general is calculated using the formula:

N in = T cm / N time,

where N in is the production rate per shift;

T cm – shift duration;

N time – standard time per unit of work (product).

Moreover, it is established in cases where the same regularly repeated work (operation) is performed during a shift. For example, the production rate for products “B” is 260 pcs. per shift, the production rate of material “C” is 85 m.

Labor rationing: just something serious

The production rate indicator is recommended to be used where the time rate indicator has a relatively small value. So, if the standard time for production of part “D” is 12 seconds per piece. and, accordingly, the production rate of this part is 300 pcs./hour.

Production standards are one of the types of labor standards that help ensure the efficient operation of organizations.

Calculation of preparatory and final time

Preparatory and final time Tpz is spent on setting up equipment to perform each processing operation. In conditions of mass production, when changeover is not required, the amount of preparatory and final time is zero.

Calculation of time standards and production standards

In other industries, setup time does not depend on the size of the batch of parts. This time can be reduced by using group processing methods, in which fasteners and cutting tools are largely preserved when reconfiguring equipment from processing parts of one type to processing parts of other types.

For CNC machines, the preparatory and final time is summed up from three components: time for mandatory techniques, time for additional techniques and time for trial processing of the workpiece. Specific values ​​can be taken from tables in technical literature.

The necessary time costs include the following: time for installing and removing the clamping device or reconfiguring the clamping elements, installing software or calling a control program (CP), checking the CP in the accelerated processing mode, setting the relative positions of the coordinate systems of the machine and the part, as well as the time for placing tools.

Additional time is spent on receiving and submitting technological documentation, familiarizing yourself with the documentation, inspecting workpieces, instructing the foreman, receiving and submitting technological equipment.

The trial processing time is formed as the sum of the time for processing the part according to the NC (cycle time) and for performing techniques associated with trial working strokes and accuracy control, calculating the correction values ​​for the position of the tips of the cutting tools and entering these values ​​into the memory of the CNC device.

Can simplify assignment Tpz, by calculating the values ​​of the preparatory and final time using formulas establishing the dependence Tpz, min from the number of instruments K pieces and processing cycle time tс = to + tв, min:

for drilling machines Tpz = 28 + 0,25TO + t c;

for boring Tpz = 47 + TO + tts;

for milling Tpz = 36 +TO+t c;

for turning Tpz= 24 + 3TO + 1,5 t c.

Main time calculation

Main time to- This is the time of direct cutting, the time during which chip removal occurs. For all types of processing there are calculation formulas, the essence of which boils down to dividing the path L(mm) of the cutting tool by the minute feed smin (mm/min), i.e. on the speed of movement of the tool relative to the workpiece (not to be confused with cutting speed). To calculate the main time, those columns of the electronic calculation table are used, in which the length of the tool strokes is entered, equal to the length of the surface being processed and the overruns of the tools; processing diameter or cutting tool diameter; the amount of allowances; cutting depth; number of tool teeth; cutting speed. The spindle rotation speed and the number of working strokes, equal to the ratio of the allowance to the depth of cut, will be calculated by the computer independently. It is most advisable to have a calculation table in the lines of which to record all working strokes, and in the vertical columns - stroke lengths, processing diameters and diameters of cutting tools, the number of working strokes, all types of feeds (per tooth, per revolution, minute), number of tool teeth, cutting speed. An example of the calculation is given in Appendix 5. Cutting speed and feed should be taken from section 7.8 “Calculation of cutting conditions”. The computer will calculate the spindle rotation speed using the formula .

It is necessary to pay special attention to the fact that the formula is entered in the cells of the calculation table to = L/s min. It applies to turning, milling, countersinking, drilling and other types of machining in which the workpiece or cutting tool rotates. When planing, broaching, gear cutting, flat grinding and in a number of other cases, the main time is determined using other formulas, which must be entered into the corresponding cells of the Excel table.