Practical experience with methods of job evaluation

Short version of the presentation by Dr. Rudolf Haller

Based on some recently conducted trainings and evaluations of workplaces with several popular methods it is discussed, which aspects of an evaluation are easily understood and used by “Non-experts”. In addition some hints are given how especially time/frequency analysis but also posture evaluation may be improved.

It is explained that some evaluation methods mix stress and strain factors. Especially the posture evaluation is a mix of stress and individual habits. Therefore it is necessary to consider also situation/posture awareness as an important way to improve a working situation.


How is work humanitarian?

Objectives of job evaluation

Work and evaluation

Ausführbar, aber nicht erträglich
Figure 1: Feasible, but not tolerable (Click to enlarge)

Damage-free means that work doesn´t lead to immediate health hazard. (Injury, accident at work)

Tolerability means that work in the long run doesn´t cause risk to health. (work-related disease, occupational disease)

How disorders develop?

Figure 2: Development of disorders (Click to enlarge)

Evaluators and evaluation methods

Reviewing by

Existing knowledge in companies


Principle decision on valuation methods

Simplicity or accuracy

Example NIOSH lifting equation: Who is NIOSH?

NIOSH Lifting Equation?

The NIOSH Lifting Equation is used to assess two-handed symmetrical/asymmetrical lifts/lowers. The revised NIOSH lifting formula uses a constant weight LC (23.2 kg) and 6 multipliers to determine a threshold for lifting (RWL).

Ermittlung des Grenzwertes für das Heben
Figure 3: Determining the threshold for lifting (Click to enlarge)

The 6 multipliers

Example task variable horizontal position (HM)

Beispiel HM
Figure 4: Example of HM (Click to enlarge)

RWL = LC x HM x VM x DM x AM x FM x CM

Horizontale Position (HM)
Figure 5: Horizontal Position (HM) (Click to enlarge)

Example: Filling a punching machine

Beispiel: Befüllen einer Stanz-Maschine
Figure 6: Filling a punching machine (Click to enlarge)

Exemplary calculation for the RWL calculation: RWLA= 20 x 0,44 x 0,94 x 0,86 x 1 x 1 x 0,95 = 6,75 kg

Sample method: Ergonomic Risk Assessment (ERA)

Ergonomic Risk Assessment (ERA): Analyse der Belastung einzelner Körperteile
Figure 8: Ergonomic Risk Assessment (ERA): Analysis of the strain of individual body parts (Click to enlarge)

A review of the risk or likelihood of overuse in a specific body part by awarding points

Classification of postures

Diese Haltungsbewertung ist leicht verständlich und anwendbar
Figure 9: This posture review is easily understood and applied. (Click to enlarge)

How strong the body is strained?

Haltungsbewertung = Beanspruchungsmessung!
Figure 10: Here is Posture rating = strain measurement! (Click to enlarge)

An example from practice

Video + photo sequences are essential for the detection of stress factors

Time / quantity structure is locally poorly detectable, since the work process (start / end) and individual variations "disturb"

Figure 11: Practical example (Click to enlarge)

What to do with reviews?

Stress or strain measurement

Figure 12: Stress (Click to enlarge)

practical significance of the partial results

Stress and strain

Belastung und Beanspruchung
Figure 13: Stress and strain (Click to enlarge)


Problems in applying the methods