What is a technique for estimating the proportion of time an employee or machine spends on different work activities?

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• What is a technique for estimating the percent of time a worker spends on various tasks?
• What do we call small groups of employees who meet to identify analyze and solve operational problems?
• What does work measurement determine?
• What technique eliminates unnecessary tasks and improves the process for completing tasks group of answer choices?

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benchmarks against which to measure a range of variables such as cost of the 
product and share of work between team members. However the work measurement technique has been criticised for 
being misused by management in determining worker compensation. The time needed to perform each work element 
can be determined by the use of historical data, work sampling or most usually time study.
10.6.1 Time Study
The purpose of Time Study is through the use of statistical techniques to arrive at a standard time for performing one 
cycle of a repetitive job. This is arrived at by observing a task a number of times. The standard time refers to the time 
allowed for the job under specific circumstances, taking into account allowances for rest and relaxation. The basic steps 
in a time study are indicated below:
1. Establish the standard job method
It is essential that the best method of undertaking the job is determined using method study before a time study is 
undertaken. If a better method for the job is found then the time study analysis will need to be repeated.
2. Break down the job into elements
The job should be broken down into a number of easily measurable tasks. This will permit a more accurate calculation of 
standard time as varying proficiencies at different parts of the whole job can be taken into account.
3. Study the job
This has traditionally been undertaken with a stopwatch, or electronic timer, by observation of the task. Each time element 
is recorded on an observation sheet. A Video camera can be used for observation, which permits study away from the 
workplace, and in slow motion which permits a higher degree of accuracy of measurement.
4. Rate the worker’s performance
As the time study is being conducted a rating of the worker’s performance is also taken in order to achieve a true time 
rating for the task. Rating factors are usually between 80% and 120% of normal. This is an important but subjective element 
in the procedure and is best done if the observer is familiar with the job itself.
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5. Compute the average time
Once a sufficient sample of job cycles have been undertaken an average is taken of the observed times called the cycle 
time. The sample size can be determined statistically, but is often around five to fifteen due to cost restrictions.
6. Compute the normal time
Adjust the cycle time for the efficiency and speed of the worker who was observed. The normal time is calculated by 
multiplying the cycle time by the performance rating factors.
Normal Time (NT) = cycle time (CT) x rating factor (RF)
7. Compute the standard time
The standard time is computed by adjusting the normal time by an allowance factor to take account of unavoidable delays 
such as machine breakdown and rest periods. The standard time is calculated as Standard Time (ST) = Normal Time 
(NT) x allowance
10.6.2 Predetermined Motion Times
One problem with time studies is that workers will not always co-operate with their use, especially if they know the results 
will be used to set wage rates. Combined with the costs of undertaking a time study, a company may use historical data in 
the form of time files to construct a new standard job time from previous job element. This has the disadvantage however 
of the reliability and applicability of old data.
Another method for calculating standard times without a time study is to use predetermined motion time system (PMTS) 
which provides generic times for standard micromotions such as reach, move and release which are common to many 
jobs. The standard item for the job is then constructed by breaking down the job into micromotions that can then be 
assigned a time from the motion time database. The standard time for the job is the sum of these micromotion times. 
Factors such as load weight for move operations are included in the time motion database.
The advantages of this approach are that standard times can be developed for jobs before they are introduced to the 
workplace without causing disruption and needing worker compliance. Also performance ratings are factored in to the 
motion times and so the subjective part of the study is eliminated. The timings should also be much more consistent than 
historical data for instance. Disadvantages include the fact that these times ignore the context of the job in which they are 
undertaken i.e. the timings are provided for the micromotion in isolation and not part of a range of movement. The sample 
is from a broad range of workers in different industries with different skill levels, which may lead to an unrepresentative 
time. Also the timings are only available for simple repetitious work which is becoming less common in industry.
10.6.3 Work Sampling
Work Sampling is useful for analysing the increasing proportion of non-repetitive tasks that are performed in most jobs. It 
is a method for determining the proportion of time a worker or machine spends on various activities and as such can be 
very useful in job redesign and estimating levels of worker output. The basic steps in work sampling are indicated below:
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1. Define the job activities
All possible activities must be categorised for a particular job. e.g. “worker idle” and “worker busy” states could be used 
to define all possible activities.
2. Determine the number of observations in the work sample
The accuracy of the proportion of time the worker is in a particular state is determined by the observation sample size. 
Assuming the sample is approximately normally distributed the sample size can be estimated using the following formula.
n = (z/e)2 * p(1 - p)
where
n = sample size
z = number of standard deviation from the mean for the desired level of confidence
e = the degree of allowable error in the sample estimate
p = the estimated proportion of time spent on a work activity
The accuracy of the estimated proportion p is usually expressed in terms of an allowable degree of error e (e.g. for a 2% 
degree of error, e = 0.02). The degree of confidence would normally be 95% (giving a z value of 1.96) or 99% (giving a z 
value of 2.58).
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Operations Management
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Work Systems Design
3. Determine the length of the sampling period
There must be sufficient time in order for a random sample of the number of observations given by the equation in 2 to 
be collected. A random number generate can be used to generate the time between observations in order to achieve a 
random sample.
4. Conduct the work sampling study and record the observations
Calculate the sample and calculate the proportion (p) by dividing the number of observations for a particular activity 
by the total number of observations.
5.Periodically re-compute the sample size required
It may be that the actual proportion for an activity is different from the proportion used to calculate the sample size in step 
2. Therefore as sampling progresses it is useful to re-compute the sample size based on the proportions actually observed.
10.7 Learning Curves
Organisations have often used learning curves to predict the improvement in productivity that can occur as experience 
is gained of a process. Thus learning curves can give an organisation

What is a technique for estimating the percent of time a worker spends on various tasks?

What do we call small groups of employees who meet to identify analyze and solve operational problems?

What does work measurement determine?

What technique eliminates unnecessary tasks and improves the process for completing tasks group of answer choices?