When to Use the Bell Curve for Performance Management

Sometimes, it takes several experiments to establish an effective system analyzing employee performance. One of the methods that some HR personnel have tried is the so-called Bell Curve grading system.

Formally known as Gaussian Probability Distribution, the bell curve method is a trigonometric plot designed to help companies rank, and classify their employees under three categories: (1) top performers, (2) average performers, and (3) below average performers.  However, there are debates that say it’s not fair to base the appraisal of employees solely on this scientific method. This short guide will help determine whether the bell curve method is right for analyzing the performance of your employees.

Use the Bell Curve If…

  1. The company wants to establish a reward system to motivate its employees.

A reward system works for many people especially if the prize is worth the effort. If you want to motivate your employees by providing monetary rewards, plaques, recognition, or gifts, the bell curve formula may help you determine the top performers who are the most deserving of these rewards.

  1. The company needs to evaluate people for promotion.

Promoting someone requires proof of competence, consistency, and readiness for the new role. The bell curve can help you determine the best candidates for promotion, and also track their work performance history for evaluation and selection.

  1. The company wants an average employee to strive harder and meet certain standards to be called a “top performer.”

Being called a top performer gives a certain feeling of fulfillment to employees – basically because people look up to the best of the best. Using the bell curve method, and disclosing the criteria you would follow, could help employees (especially the average performers), to strive harder and be part of the prestigious list.

  1. The company wants to identify below average performers to help them get better.

It’s never wise to tolerate poor performance especially in a busy organization. The bell curve formula can help you determine the least performing employees in the company, as well as the areas of their weakness. You can discuss these low points with the employees and also find ways to help them perform better in those areas.

  1. The company is a big corporation.

The bell curve formula has worked for big corporations because there’s a large risk for thousands of employees to underperform. It’s also quite a challenge for the HR personnel to evaluate the employees of a big corporation using different methods because of their headcount.

Do Not Use the Bell Curve If…

  1. The company would like to promote collaboration or team work in the office.

Let’s admit it. The bell curve promotes competitiveness. An employee needs to outdo the work of others to be one of the top performers. Hence, the company shouldn’t use this method if you genuinely would like to promote collaboration and team work in your company.

  1. The company is small or a startup.

Most of the time, the bell curve is not advisable for small or startup companies with less than 300 employees. Some experts say that the analysis and categorization of employees wouldn’t be done properly with that headcount. For example, if a team is composed of only three employees, then one would be the top performer, the other one is the average performer, and the one is the least performer even if their scores are not that far from each other because the bell curve requires the evaluation to be evenly distributed. Also, when the results are negative, some employees tend to feel discouraged rather than motivated.

  1. The company has tried it, but the employees hate it.

If most of your employees are not happy with the bell curve, then it’s probably not for your organization. Some employees become too pressured with the criteria attached to the bell curve, and eventually, they become more unproductive. Remember never to compromise your employees’ delight in going to work and doing their job for the sake of an easy-to-use and popular evaluation system.


Analyzing the performance of employees requires a systematic method. Whether it’s the bell curve or not, we hope that every company evaluates their people fairly and comprehensively.