Time Study Basic
Time study is a time measurement system for completing a certain operation by an operator to carry it out at a defined rate of performance.
Essential Tools of Time Study:
For the time study of a running style in the production line, you need to arrange the following tools:
01. Stopwatch
02. Production process sheet or operation breakdown
03. Calculator
04. Clipboard
05. Pen or pencil
Preparation for Time Study:
There are some crucial points to consider before starting the time study, which are given below:
01. Inform the line supervisor before timing the operator.
02. Ask for permission and be polite with the operator.
03. Don’t create any sort of pressure on the operator; make the operator feel relaxed.
04. Stand in the right position and make sure that other operators are not feeling any problems doing their tasks.
Before taking the time of an operation, four key points need to be checked. If any of these points are missing or lacking in the production line, please don’t start the time study. The four points are:
01. Are material, machine, and tools available in the production line?
02. Is the production line environment favorable for the operator? For example, lights are damaged above the stitching operator’s head. In this situation, the operator is not able to work properly.
03. Is the operator mentally and physically fit for doing this operation?
04. Does the operator have enough skill to do this operation?
Doing things when you start time study:
01. Do not stand too far from the operator; usually stand diagonally between 1.5-2.0 meters distance from the operator.
02. In shoe manufacturing, observing six pairs is enough. You can take more if you wish.
03. Note down the relevant details about the machine and method.
Steps of time study:
Step 01: Take proper preparation as mentioned above in this article.
Step 02: Record the time of six consecutive operation cycles, also known as Cycle Time (CT). During the timing of the operation, if you find any sort of abnormality such as a quality issue of the product, machine problem, etc., then you need to take the time again. Remember that abnormal time is not included in standard time. Note down the operator rating based on operator skills.
Step 03: Calculate the basic time of each operation. The formula for basic time is:
Basic Time = Observed Time × Observed Rating
Observed Time = Total Cycle Time / Number of cycles
Suppose you take 6 pairs of upper round skiving operation cycle time:
1st pair – 230 seconds
2nd pair – 225 seconds
3rd pair – 240 seconds
4th pair – 220 seconds
5th pair – 225 seconds
6th pair – 230 seconds
Total Cycle Time = 230 + 225 + 240 + 220 + 225 + 230 = 1370 seconds
Observed Time = 1370 / 6 = 228.33 seconds
Based on the operator’s skills, you give a rating to the operator of 90%, then
Basic Time = 228.33 × 90% = 205.5 seconds
In this way, you can calculate the basic time for all operations.
Step 04: Calculate the Standard Time of each operation. The formula for Standard Time is:
Standard Time = Basic Time × (1 + Allowance Time)
Allowance time is needed because of the personal needs of the operator, frequent machine adjustments, or machine allowance, and fatigue. Normally, the allowance time varies from 5-20% of basic time. It totally depends on the factory authority to fix the allowance time based on production line and process conditions. Let’s assume the allowance time for the above upper skiving operation is 6%, then
Standard Time = 205.5 × (1 + 6%) = 217.83 seconds
In this way, you can find out the standard time for all production operations. The formula for total standard time is:
Total Standard Time = Sum of All Operations Standard Time
Using this total standard time, you can easily find out the Production Per Hour (PPH) of this style:
PPH = 3600 / Sum of All Operations Standard Time