What is Performance Rating in Time Study?

What is Performance Rating?

Performance Rating is the assessment of an operator’s working pace compared with a defined normal performance level during a time study.

It helps an Industrial Engineer adjust observed time when the operator is working faster or slower than the normal pace.

In simple terms

If an operator completes a task unusually fast, the observed time may be lower than the time required at normal performance.

If the operator is slower than normal, the observed time may be higher.

Performance rating helps account for this difference.

Simple Example

Observed Time = 50 seconds

Performance Rating = 120%

Normal Time:

50 × 1.20 = 60 seconds

So, the operator’s 50-second observed cycle corresponds to 60 seconds at normal performance.

Why It Matters

Performance rating is important when establishing:

• Normal Time
• Standard Time
• Manpower requirements
• Line balancing
• Productivity standards
• Labor costing

Important Insight

Performance rating should not be confused with employee performance appraisal.

It is not about judging whether an operator is a “good” or “bad” employee.

It is about evaluating the pace of work during a specific time-study observation.

Factors an IE May Consider

• Working pace
• Skill and familiarity with the task
• Smoothness of movement
• Effort required
• Consistency of the work method

Good Practice

To make rating more reliable:

• Define the standard method first.
• Observe several cycles.
• Use trained Industrial Engineering personnel.
• Avoid rating based on a single observation.
• Apply the same rating principles consistently.
• Validate the resulting standard with actual production conditions.

Practical Insight

A 50-second cycle does not automatically mean a 50-second standard.

Understanding the operator’s working pace is one of the key steps between observed time and a meaningful standard time.