Bell Curve a curse to Organisation ?

Bell curve which is the most common evaluation methodology used by companies has always been a hot topic for debate for CEO and HR managers. Many CEOs who express their dis-concern of using such methodology for employee evaluation, at the same time MNCs continue to use Bell curve for their evaluation.

For readers who are well not aware of bell curve, here is a short para on bell curve. Although internet offers you many articles on bell curve and its pros and cons.

Bell curve is "Strategic distribution" of their employees forcing the Managers to categorize and place their employees into each of the categories "Non-performers" , "Average Performers" , "Top Performers".

Example : There are 20 people in a department, the manager / leader of this department MUST categorize these 20 people into each of the categories

• Non - Performers (10%) : 2 people 
• Average Performer (70%) : 14 people 
• Top Performer (20%) : 4 people 

Let's imagine Bell Curve used in schools : 

Students would be evaluated and categorised into A, B, C, D irrespective of their marks. All get to write the same paper which means the challenges for all of them is same, but this isn't the case at office where all employees of same dept are evaluated on same scale irrespective of their roles and challenges. 

Now let's get back to school, all 4 students of a particular class score above 90 which is a great score, but according to Bell Curve you are forced to categorize them and one of these students will be a poor performer / poor student. Is this fair ? Am not answering, but please think.  You might answer that is why "percentile" concept is used. Then i would ask "the paper was same and time to complete this task was also uniform to all, is this the same at work ? "  Again, am not answering this one too... 

See the below graph, there are 2 departments and let's consider there are 4 employee in each department. The graph is measure vs competency or potential of the employee. According to Bell Curve these 4 need to be categorized into poor performer , below average, above average and top performer. 

As you can see depicted in the graph an employee 4.A in Dept A is categorized as poor performer but is more competent and has higher potential than employer 1.B of Dept B who is rated as above top performer employee. Therefore,  employee 4.A gets completely demotivated when he gets aware that employee 1.B is rated better than him / her and gets a higher hike percentage than him / her. This is the start of the company when the employee starts exploring options out of the division / out of organization itself. 

From the HR angle 4.A is a poor performer and therefore doesn't impact much to organisation if he/she leaves. 

This is just a brief of Bell Curve which has been a topic of debate at various HR forums and off late some MNC have moved away from it, but still many companies follow the same and its time that they too move out and start adopting other evaluation methodology benefiting both  the organisation and employee. These are "My Thoughts", do share in "Your Thoughts" as well.