A time study measures how long an operator takes to complete an operation. In garment factories it is often called a capacity study, because the result tells you how many pieces an operator can make per hour.
Before you start
- Explain to the operator what you are doing and why. People work more naturally when they are not worried.
- Make sure the method is correct and the machine is set up properly.
- Agree the start and end point of the cycle, for example "pick up the part" to "place the finished part on the bundle".
Step 1 - Break the operation into elements
Short elements are easier to time and help you see waste later:
- Pick up and align parts
- Sew
- Trim and dispose
Step 2 - Time at least 10 cycles
Record each cycle. Remove cycles with obvious interruptions (thread break, talking, missing parts), but write down why - those delays are real and belong in the allowance or NPT records.
Step 3 - Rate the performance
Rating compares the operator's pace with a normal pace of 100%. A skilled, fast operator may be rated 110-120%; a slow learner 80-90%.
Tip: Rate the pace, not the person. Watch hand speed, confidence and smoothness of motion.
Step 4 - Add allowances
Allowances cover time the operator needs but that is not part of the cycle:
| Allowance | Typical range |
|---|---|
| Personal needs | 5% |
| Fatigue | 4-6% |
| Machine & bundle delays | 3-6% |
Many factories use one combined figure of 10-20%.
Step 5 - Calculate
Formula: Normal time = Average observed time × Rating ÷ 100. Standard time = Normal time × (1 + Allowance ÷ 100). Capacity per hour = 60 ÷ Standard time (minutes).
Example: average 30 s, rating 100%, allowance 10% → normal time 0.50 min, standard time 0.55 min, capacity 109 pieces per hour. If the bulletin SAM is 0.50 min, the operator's efficiency is 0.50 ÷ 0.55 = 90.9%.
Use the result
- Put operators where their capacity fits the line's target.
- Find operators who need training.
- Update the capacity after training or a method change.
Try the numbers in our free time study calculator.