Human Performance Evaluation

Human Performance Evaluation is used to identify factors that influence task performance. It is

most frequently used for man-machine interface studies. Its focus is on operability and work environment,

rather than training operators to compensate for bad conditions. Also, human performance evaluation

may be used for most occurrences since many conditions and situations leading to an occurrence ultimately

result from some task performance problem such as planning, scheduling, task assignment analysis,

maintenance, and inspections. Training in ergonomics and human factors is needed to perform adequate

human performance evaluations, especially in man-machine interface situations. Appendix H discusses this

technique.

Kepner-Tregoe is used when a comprehensive analysis is needed for all phases of the occurrence

investigation process. Its strength lies in providing an efficient, systematic framework for gathering,

organizing and evaluating information and consists of four basic steps:

Situation appraisal to identify concerns, set priorities, and plan the next steps.

Problem analysis to precisely describe the problem, identify and evaluate the causes and

confirm the true cause. (This step is similar to change analysis).

Decision analysis to clarify purpose, evaluate alternatives, assess the risks of each option

and to make a final decision.

Potential problem analysis to identify safety degradation that might be introduced by the

corrective action, identify the likely causes of those problems, take preventive action and

plan contingent action. This final step provides assurance that the safety of no other

system is degraded by changes introduced by proposed corrective actions.

These four steps cover all phases of the occurrence investigation process and thus, Kepner-Tregoe

can be used for more than causal factor analysis. Separate worksheets (provided by Kepner-Tregoe)

provide a specific focus on each of the four basic steps and consist of step by step procedures to aid in the

analyses. This systems approach prevents overlooking any aspect of the concern. As formal Kepner-

Tregoe training is needed for those using this method, a further description is not included in this

document.

The root cause analysis enables the improvement of reliability and safety by selecting and

implementing effective corrective actions. To begin, identify the corrective action for each cause; then

apply the following criteria to the corrective actions to ensure they are viable. If the corrective actions are

not viable, re-evaluate the solutions.

Will the corrective action prevent recurrence?

Is the corrective action feasible?

Does the corrective action allow meeting primary objectives or mission?