Application of SOTIF for the assessment of HMIs

The Ministry of Infrastructure and Water Management in The Netherlands is considering the possibility of adding Human Factors aspects (HF) to the type approval process of passenger cars and commercial transport (cars, buses and trucks) that are equipped with driver assistance systems or automated vehicle systems. In these systems, the interaction with the driver plays a critical role with regards to the safe usage of these systems. Therefore, an evaluation of these interaction processes between the vehicle and driver are under consideration to become a part of the type-approval process.

Safety Of The Intended Functionality (SOTIF) is a standard that enables the analysis of a system for possible functional insufficiencies during its normal functioning. SOTIF is about making sure a system is safe even when it’s working as designed. Sometimes, a system can still cause danger not because something broke, but because it wasn’t designed to handle certain situations well enough. For example, a self-driving car might not recognize a pedestrian in unusual lighting, not because the sensors failed, but because the developer of the software didn’t expect that situation to occur, and hence did not design the system to function in such a situation. SOTIF looks at those kinds of risks. This is different from functional safety, which is about what happens when something in the system actually breaks or stops working. Therefore, this is a complementary approach that is considered important in the development of automated driving systems and is also used extensively within the industry. The analysis aims to identify and prevent potential inadequacies in the system or opportunities for misuse by the user.

The Ministry raised the question of whether and how the SOTIF approach can be used to evaluate the quality of interaction processes between the vehicle and the user, in the context of automated driving systems. Pursuant to this, Rijkswaterstaat requested TNO to undertake a research project to further investigate the possibilities of such an approach.