Rating the Performance of Workers: 6 Methods

The following points highlight the top six methods of rating the performance of workers. The methods are: 1. Speed Rating. 2. Westinghouse System of Rating. 3. Synthetic Rating. 4. Objective Rating. 5. Skill and Effort Rating. 6. Psychological Evaluation of Performance Level Rating.

Method # 1. Speed Rating:

In speed rating, the speed of the movements of a worker is the only factor to be considered. The time study engineer observes the speed of the movements of the worker against a standard expected pace or speed and notes the relationship between them as the rating factor. Rating factor can be applied to different elements.

Rating Factor = Workers speed/Speed expected from the worker

Normal Time = Observed time x Workers speed/Speed expected

Method # 2. Westinghouse System of Rating:

This system of rating developed at Westinghouse is based on four factors.

These factors are:

a) Skill.

b) Effort.

c) Conditions.

d) Consistency.

Each factor is then subdivided into super skill, excellent, good, average, fair and poor. Each sub-factors are attached with numeric values. The average time obtained from time study is normalised by applying the sum of the ratings of the four factors.

The table is as follows:

From time study, let the average time = 0.95 minutes and the various time factors are:

Good Skill (Cl) = + 0.06

Excellent Effort (Bl) = + 0.10

Good Condition = + 0.02

Good Consistency = + 0.01

Algebric Sum = + 0.19

The algebraic sum indicates that the worker is 19 percent above average. If the worker gets negative algebraic sum, he is considered to be below average.

Method # 3. Synthetic Rating:

In this method, performance of the worker is rated from the values already known by Pre-determined Motion Time System (P.M.T.S.). In this procedure, time study is done in the usual manner and then actual time obtained for certain elements from this study is compared with that of known standards. A ratio is established between these two values and average ratio is calculated.

Performance Rating Factor = PMTS value for the element/Average actual time values for the same element

i.e. R = P/A

Method # 4. Objective Rating:

Under this system, rating is done in two stages. In first stage, operator’s speed is rated without considering any difficulty in making the job.

In the second stage, an adjustment factor is to be applied to compensate the operators difficulty. Job difficulties are divided into six classes.

A table provides the percentage of adjustments to be made for each of these six factors, namely:

i) Amount of body used.

ii) Foot movements.

iii) Bimanualness.

iv) Eye-hand coordination.

v) Handling requirements.

vi) Weight.

For example if the selected time for an element is 0.30 minute, the pace rating is 1.10 percent and if the sum of all secondary adjustments amount to 20 percent then the normal time will be calculated as follows

Normal time = Average time x Pace rating x Difficulty adjustment

= 0.30 x 1.10 x 1.20

= 0.396 minute.

Method # 5. Skill and Effort Rating: (Bedaux System):

Under this system, the study time engineer observes and judges how fast the operator performs the motions involved and also his skill. Hence it is called as “Skill and Effort Rating”. This system was introduced by Charles E. Bedaux in 1916.

The author did not consider time as basis, but he introduced ‘B’ values (the efficiency of each work element is estimated in ‘B’ values). ‘B’ values represent a standard minute which contains (i) work component, and (ii) relaxation component. Only human effort is measured by this system.

Method # 6. Physiological Evaluation of Performance Level:

Under this method, the performance level of the worker is estimated physiologically. Many studies have revealed that there is relationship between physical work and amount of oxygen consumed by the operator. There is change in heart beating rate depending on the physical work and it is assumed that it is a reliable index to measure muscular activity.

Thus the oxygen consumed and the heart beat rate depend on the severity of physical labour. Thus performance level of a worker can be estimated using this correlation because heart beat rate and oxygen consumption increase when the worker is at working level. When work ends, recovery begins and the heart rate and oxygen consumption return to normal resting level.