Validation of Ergonomic Criteria for the Evaluation of Simplex Systems

The increasing complexity of interconnected systems, organizations and environmental instability open on one hand new functional features and unexpected levels of systemic efficiency, but on the other hand leads to great challenges to maintain a good level of usability. We assume that the complex systems should be adapted to human capacities and goals through a structural integration of such complexity by the interactive systems. These systems should be both: structurally complex from technological and organizational standpoint; and conceptually simple from operator’s standpoint, in other words it should be simplex. In order to design an efficient balance between complexity and simplexity a new kind of user centered methods are necessary. But, current available methods in ergonomics to assess Human-Simplex System Interactions (HSSI) are limited in the field of Human Oriented Approach of Complexity, also called Human System Integration (HSI). In this paper, we present an experimental assessment of an evaluation method based on a set of Ergonomic Criteria able to support human factors specialists during an inspection task of complex systems. This experimental study aimed to assess if these Ergonomic Criteria are useful and efficient. Thirty-one HSI Designers performed an ergonomic inspection of two Simplex Systems in order to capture a maximum of usability/assistance flaws. The results show that the criteria are reliable and valid. The use of these Criteria allowed to identify more flaws and also more flaws shared between assessors. Nevertheless, the satisfaction results revealed the need to improve the level of maturity of these criteria.