Hi!
I had the same questions before, i.e. the relationship between the Bell (Normal Distribution) Curve and Performance Management System.
Now, as a PMS designer, implementor, and consultant, I am a strong advocate for the link between PMS and recognition, rewards, or sanction.
Now why do organizations use the Bell Curve or Normal Distribution Curve?
One good answer is: the normal distribution curve is the easiest to use, easy to understand, and easy to implement. It is simply arranging the rated employees from the one getting the highest rating to the one who got the lowest and distribute them by percent in the various alloted columns (in some, they use FOUR (4) while other use SIX (6)). This facilitates grouping or classification of employees in terms of amount or types of rewards/ sanctions to be given.
The problem with the use of the Bell Curve is when it is allowed to influence and "LEAD to the CHANGE" of the actual Perofrmance RATING.
As such, in our own PMS, we make it a point that the Bell Curve is used independent of the rating. It is used when the results of the PMS will be utilized to guide the distribution of the total amount of rewards budgeted by the organization for a given year.
We have a detailed discussion of this subject matter at The Policy Center a year ago. Visit the site (
http://finance.groups.yahoo.com/group/policy_cener) and look for the old discussion threads on this subject.
Best wishes.
Ed Llarena, Jr.
Managing Partner
Emilla Consulting
Best wishes.