Industrial engineering formula
Observed time adjusted by the performance rating, before allowances are added. It is the work content at standard pace.
Basic time = observed time × rating / 100
| Symbol | Meaning | Unit |
|---|---|---|
| t_obs | Observed time | min or s |
| R | Performance rating | % |
Use it as the middle step of time study, and whenever you need to compare work content without allowances.
An operator averages 24 seconds per cycle and is rated at 110%.
Basic time = 24 × 1.10 = 26.4 seconds = 0.44 minutes.
A rating above 100% means the operator worked faster than standard pace, so the standard time is longer than what was observed.
How to carry out a stopwatch time study on a sewing operation: break it into elements, take enough cycles, rate the operator's pace, add allowances and arrive at a standard time. With a worked example and the mistakes that spoil results.
A step-by-step method to calculate operation and garment SMV from time study: define the method, time the cycles, remove abnormal readings, rate performance, add allowances and check the result.