Time per unit

The time per unit , also part time (symbol t _e ), is a term from manufacturing technology .

Target time for people and resources

Resource time per unit

Time per unit for man

The piece time is the time required to process a single service unit . It generally refers to the unit of measure 1, 100 or 1000 pieces.

Definition of equipment

For equipment , the set timeframe for a lot together as the addition of setup time and the number multiplied chunk of time .

${\displaystyle t_{f}=t_{r}+n\cdot t_{e}}$

The production costs are then calculated from the hourly machine rate multiplied by the batch production time.

Definition of personnel expenses

The definition of the REFA association is most widespread in German-speaking countries:

"The time per unit is the standard time for the execution of a process by humans" ${\displaystyle t_{e}}$

- REFA

Default time means a planned or target time in which the work should be carried out. This work is carried out in a defined process for which the standard time applies. The parameters are fully described by the work system .

According to REFA, the time is composed as follows

${\displaystyle t_{e1}=t_{g}+t_{er}+t_{v}}$

in which

${\displaystyle t_{g}}$the bottom times

${\displaystyle t_{er}}$the recovery time

${\displaystyle t_{v}}$are the distribution time .

This time is a target time for people to carry out a work task within a work system. This time can be a formal time and (e.g. for technical wage reasons) deviate from the measurable time.

These times are determined in different ways, for example according to the REFA methodology of the work study , by way of a time study , from planned time catalogs or by comparing and estimating .

use

The time per unit is used for different purposes. The REFA association names planning, management, control and remuneration , plus cost accounting .

The piece time does not necessarily have to be a measured or measurable time, but can also be a formally specified time (e.g. for reasons of payroll accounting).

In the (preliminary) calculation , the time per unit has an effect because either the useful life of a resource is included in the manufacturing costs by multiplying it by the hourly machine rate , or the pro rata production wages . The control calculation with actual times is part of the post calculation . An object-related time study is often not used for the calculation, but the time is determined from time modules .

The principle of economic efficiency requires that the production of an operation takes place as quickly as possible (low resource consumption). This requirement can conflict with the principles of quality and adherence to deadlines , the other two cornerstones for assessing the performance of production systems and ultimately the company .

Individual evidence

1. ↑ ^{a b c} REFA: Methodology of work studies. Part 2: Data Discovery. Carl Hanser Verlag, Munich 1978, ISBN 3-446-12704-6 , p. 52.
2. ↑ Stückzeit , the industry portal for the Swiss machine, electrical and metal industry, industrie-schweiz.ch