Industrial Engineering

Subjective Workload Measurement in Workplace Using NASA TLX

NASA TLXPicture source: http://www.bing.com

By:
1. Ericson Wei 1801418811
2. Frans CartenzIriandy Sitorus 1801415583
3. Riyan Phanggestu 1801404996
4. Sugianto 1801430092

NASA Task Load Index (NASA-TLX) is a subjective method of workload measurement in questionnaire form, created by Sandra G. Hart from NASA-Ames Research Center and Lowell E. Staveland from San Jose University in 1981. NASA-TLX is a multidimensional rating procedure that divides workload into 6 dimensions: Mental Demand, Physical Demand, Temporal Demand, Effort, Own Performance, and Frustration. NASA TLX is divided into 2 steps, namely Paired Comparison and Event Scoring. Compared to other objective methods, NASA TLX is fairly simple, requiring less time and cost. Researchers only haveto make the questionnaire and distribute it to the respondents. The important things to be reminded of NASA TLX is that this method is only accurate to measure and compare workload of each professions or job types, not each employee.

The purposes of NASA TLX are:

  1. To understand the function and duty of man and machine based on the prediction of mental workload
  2. To know the minimum limit of work performance
  3. To reduce the probability of work accident
  4. To give weight and rate to mental workload performance of a job

According to Hancock and Meshkati (1988), these are the steps of mental workload measurement using NASA TLX:

  1. Giving explanation of mental workload indicators on the questionnaire
  2. Giving weight
  3. Rating
  4. Calculating product value
  5. Calculating weighted workload (WWL)
  6. Calculating average WWL
  7. Interpreting score

Advantages and disadvantages of NASA TLX:
Advantages:
1. High validity
2. Easy to understand and apply
3. Simplicity and easiness in using the method

Disadvantages:
1. Adapted from evaluator
2. Unstable
3. Subjective