I have come across the concept of ‘score card’ for
employees in an organization. It is an employee performance-assessment tool.
Each employee’s work is categorized in to some parts and each part is given
some weightage depending on its significance. The employee is allotted with a score in each part of the work depending
on his performance in that work. Part-wise performance-percentages and overall performance-percentage are calculated and based on these parameters, his salary-hike is decided for the coming fiscal. Can we take the average of all the part-performance
percentages to get the overall-performance figure?
Let us consider
the following scenario:
The deciding
parameters are Work Efficiency, Punctuality, Analysation skills and Problem
solving skills each having equal weightage of 25%. And an employee has got the following
scores:
Parameter
|
Weightage
|
Employee score
|
Part %
|
Work efficiency
|
25
|
20
|
80%
|
Punctuality
|
25
|
25
|
100%
|
Analyzation skills
|
25
|
15
|
60%
|
Problem solving skills
|
25
|
20
|
80%
|
The overall
performance can be calculated straight-away like
Total score
achieved by employee/ total max. Score = (20+25+15+20)/(25+25+25+25)
= 80%
I can also find
it by taking average of part percentages:
(80+100+60+80)/4
= 320/4 = 80%
Now I
change the weightages allotted to the parameters like this:
Parameter
|
Weightage
|
Employee score
|
Part %
|
Work efficiency
|
50
|
40
|
80%
|
Punctuality
|
20
|
20
|
100%
|
Analyzation skills
|
10
|
6
|
60%
|
Problem solving skills
|
20
|
16
|
80%
|
Overall
performance % = (40+20+6+16)/(50+20+10+20) = 82%
But if I do it by
taking average of individual percentages, I will get (80+100+60+80)/4 = 320/4 =
80%
Where
has it gone wrong?
Here
comes the concept of weightages. I need to take care of the weightage of each
part. In the first problem, the weightage given to each part is 25 and hence weightage
fraction for each part is 25/100 = ¼. So when I say that the overall average is
(80+100+60+80)/4, it really meant this:
“(1/4)*80
+(1/4)*100 +(1/4)*60 +(1/4)*80” Here I multiply the part-percentages with the
respective weightage.
Coming to the
second problem, the weightage for the first part is 50/100 = ½, weightage for
second part is 20/100 = 1/5, weightage for third part is 10/100 = 1/10 and
weightage for fourth part is 20/100 = 1/5.
So the overall-performance = (1/2)*80 + (1/5)*100
+ (1/10)*60 + (1/5)*80 = 40+20+6+16 = 82%
No comments:
Post a Comment