Work Measurement
Time Study
Time study provides standard time, which is the amount of time it takes workers to complete a job in a standard way. A good estimate requires standard times for various jobs.
- Labor, machinery and equipment requirements
- Daily, weekly or monthly material requirements
- Cost of production per unit as an input to improve manufacturing or purchasing decisions
- Work budget
- Worker Efficiency and Incentive Payments.
Solved Example: 9058-01
Time study is carried out by: (ISRO IPRC Tech Asst Mech Dec 2016)
A. Finding all significant regarding the job, work, place, machine tool, etc
B. Breaking up each operation into small elements, which can be measured accurately
C. Observing and recording the time taken by the operator for an operation
D. All the above
Correct Answer: B
Solved Example: 9058-02
Time study in industries is performed to: (MPSC AMVI Paper IV: 2005)
A. Improve efficiency of workers
B. Set the time standard
C. Simplify the work method
D. Measure time variation in the job
Correct Answer: D
Predetermined Time Systems
- Predetermined Motion Time Systems (PMTS) is a work measurement technique whereby time established for basic human motions are used to build up the time for a job at a defined level of performance.
- PMTS also called predetermined Time System (PTS), is a database of basic motion elements and their associated normal time values, together with a set of procedures for applying the data to analyze manual tasks and establish standard times for the tasks.
- They include motions such as reach, grasp, move and release.
- One time is indicated for a given motion, irrespective of where such motion is performed.
- It avoids both ratings and direct observations, can lead to more reliability in setting standard times.
- PMT systems are not too difficult to apply and can be less time consuming than other methods.
Solved Example: 9059-01
Which one of the following is not a technique under Predetermined Motion Time System (PMTS)? (BPSC AE Paper VI Mech Mar 2022)
A. Work factor
B. Synthetic data
C. Stopwatch time study
D. MTM
Correct Answer: C
Solved Example: 9059-01
A technique of Work measurement in which times established for basic human motions are used to build up the time for a job at the defined level of performance is called: (UPRVUNL JE ME Oct 2021 Shift II)
A. Work sampling
B. Time study
C. Predetermined motion time study
D. Analytical estimating
Correct Answer: C
Work Sampling
Applications of Work Sampling:
- Activity and Delay Sampling
- Performance Sampling
- Work Measurement
- Take a preliminary sample to obtain estimates of parameter values.
- Compute the sample size required.
- Prepare a schedule for random observations at appropriate times.
- Observe and record worker activites.
- Determine how workers spend their time.
- Less expensive than time study
- Observers need little training
- Studies can be delayed or interrupted with little impact on results
- Worker has little chance to affect results
- Less intrusive
- Does not divide work elements as completely as time study
- Can yield biased results if observer does not follow random pattern.
- Less accurate, especially when job element times are short.
Solved Example: 9057-01
The error estimate (e) in work sampling varies with sample size (n) as: (UPPSC AE Mech 2013 Paper I)
A. $e \propto \dfrac{1}{n}$
B. $e \propto \frac{1}{{\sqrt n }}$
C. $e \propto \sqrt n$
D. $e \propto \frac{1}{{{n^2}}}$
Correct Answer: B
Solved Example: 9057-02
In a work sampling study of a worker, the information available are as follows:
- Total time of study: 30 hour,
- Number of items produced: 320,
- Total number of observations: 1000,
- Number of observations when worker is found working: 850 and
- Average performance rating: 105%.
A. 2.23
B. 4.19
C. 5.58
D. 6.60
Correct Answer: C