### To calculate the headcount, it is necessary to determine the labor costs for the work

The work of an architect and artist, designer and programmer, accountant and engineer, turner and electrician, loader, and storekeeper is measured by the number of working hours or minutes spent on it. To determine labor costs, it is necessary to calculate the number of operations of the same type performed in the course of work and multiply them by the average amount of time to complete one operation – the time norm. Repeat the procedure for all operations to be performed by the employee.

Example: a worker has to make 100 items of type A and 200 items of type B. The standard time for making item A is 0.5 hours, the standard time for making item B is 1 hour… Labor costs for the manufacture of a batch of products A and B are calculated as follows: 100 * 0.5 + 200 * 1 = 250 hours.

### Calculation of the number of personnel assumes the use of average norms

Employees perform work at different speeds – some faster, some slower. It is incorrect to set a rate for the best or worst employee. Optimal is the definition of the norm for the “average successful” employee. It does not matter what rate appears in your calculations – time rate, production rate, service rate, headcount rate, or standardized task.

### The number of staff units is calculated as the ratio of labor costs to the working time fund of one employee

The universal formula for calculating the number of employees is as follows – labor costs for a certain amount of work/fund of working time for the period during which this work must be performed.

Example. The labor costs are 250 hours, we need to calculate how many workers will complete it in a week, assuming that the work time of each of them is 40 hours/week. The calculation will look like this – 250/40 = 6.25. If we want to complete the specified amount of work in a week, we need 6.25 staff members.

### If presence at the workplace is more important than the amount of work, labor costs are equated to the number of hours according to the work schedule

It’s simple – we calculate the number of working hours that should be worked and divide it by the working time fund for the period.

Example. If you need to calculate the number of security guards working around the clock 365 days a year, then the number of hours that must be worked is calculated using the formula 365 * 24 = 8760 hours. To calculate the headcount, we use the number of working hours for a 40-hour workweek per year (1970), taken from the production calendar. The calculation of the number will look as follows – 8760/1970 = 4.4 staff units.

### When calculating the headcount, we take into account work breaks and heterogeneity of working hours

Working hours include several types of working hours – preparatory and final, workplace service time and operational time, as well as breaks that are part of working hours – rest breaks and personal needs and technological breaks. It follows from this that, when calculating the amount of work that an employee can perform during working hours, it is necessary to take into account the heterogeneity of working hours. Working time is spent both on preparing the workplace and receiving the task, and on performing random and unproductive work – correcting errors, collecting missing information, and on breaks provided for by the operating mode. Accordingly, the number of personnel should be calculated taking into account the amount of working time the employee has, minus all planned and unplanned losses.

Example. According to your calculations, one call center operator working 8 hours a day can receive 200 calls a day. But when analyzing the working time, it turned out that receiving calls (operational time) takes only 50% of his working time – the rest of the time takes preparatory and final time, servicing the workplace and breaks. In this case, to receive 200 calls, you will need not one, but two staff units.

### When calculating the headcount, we use the absenteeism rate as needed

Example. If you decide to hire 12 drivers for 12 buses, expecting all 12 buses to be on the line, it would be a mistake. One car will always be idle because at best eleven drivers will be at work at the same time – no one has canceled the right to annual leave. For the correct calculation of the size, it makes sense to apply the “absenteeism rate” equal to 1.12. 12 * 1.12 = 13.4 staff units. Conclusion – the staff must have at least 13 drivers.

We calculated the absenteeism rate used in the example, taking into account that 28 vacation days per year per employee is 1/12 (0.08) of the annual working time fund, except for the vacation, we took into account the losses due to temporary disability that were laid in the amount of 2 weeks per year – this is 1/24 (0.04) of the annual fund of working time. According to statistics, the absenteeism rate of your company’s employees may turn out to be more or less than 1.12, or you may not use it at all for calculating if your employee’s absence from work during vacation, illness, or for other reasons is not critical.

### When calculating the headcount, if necessary, we use the coefficient of labor productivity

The mathematical dependence of the number on labor productivity is simple – the higher labor productivity, the fewer workers are required to perform a certain amount of work, and vice versa – the lower labor productivity, the more workers will have to be hired.

Example. You need 10 workers to do a certain amount of work. But you are sure that their labor productivity will exceed the target by 115%. In this case, you will calculate the required number as follows: 10 / 1.15 = 8.7 staff units.

### We consider the workload to be optimal in the range from 85% to 115%

The workload can be understood as the ratio of the amount of work performed by an employee to the working time fund. This figure also reflects the number of staff members to perform a certain amount of work.

Example. A worker takes 156 hours a month to complete a production task, with a working time fund of 168 hours a month. Its load is 156/168 = 93%

There can be more or less work, it is not always possible to achieve a uniform 100% workload. It is logical to assume that with fluctuations in workload in the range of 85-115%, the average monthly workload should be 100%. Following this logic, it is possible to talk about the introduction of an additional staff unit if the workload exceeds 115%.

### We count on a certain amount of work

If the volume of work differs due to seasonality, by shifts (night-day) or even by days of the week (Friday – calm, Monday – emergency), this must be taken into account in the calculation. If this is not taken into account, the workers will either be overloaded or will be idle.

### The accuracy of the headcount calculation is determined by the task to be solved

If you need to calculate the size of a department that has several hundred employees, it may make sense to spend time developing norms using labor-intensive methods of labor rationing such as timing and photograph of the working day. But this is a long and complex work that will take several months without any guarantee that the results will pay off after the implementation of the regulations. Often, in order to justify the number of units, it is enough to present a calculation in which the norms obtained by the total methods of standardization, in particular, by the method of expert evaluation, will be used.

### Before calculating the number of employees, exclude losses of working time

Losses of working time can arise due to violations of labor discipline – late and early departures from work, unofficial conversations, shortcomings in the organization of work, etc. For a correct calculation of the number, these losses should be excluded from the working time fund.

### When calculating norms by an expert, we use a special formula

The formula for calculating the norm by the expert assessment method is as follows – H = (3 * Tmin + 2Tmax)/5, where Tmin, and Tmax – the minimum and maximum value of the norm in the opinion of an expert or a group of experts. The resulting value will be more accurate than the arithmetic mean.