An assessment framework for development processes of safety-critical system functions applied to a model-based safety-critical middleware

This paper deals with an assessment framework to quantifying the impact on development costs by using the selective middleware approach (SMW) for safety-critical system functions. The development of safety-critical system functions is troublesome and time-consuming. Most of the effort is spent on the development and verification of functions such as redundancy management or master/slave management to provide a fault-tolerant platform behavior. The SMW provides an efficient development method for platform management as a middleware used for safety-critical system functions on IMA. It is based on a knowledge-based toolchain, which automatically derives the instance of the platform management middleware from a manually designed high-level system architecture model. In addition to the platform management software, the required design artifacts and verification artifacts are automatically generated. Since the SMW approach supports the software development process with highly automated process activities, it is investigated to what extent the SMW approach reduces the development effort. Therefore, a detailed assessment framework is developed, which covers and evaluates its impact on development phases. Hence, four evaluation views are defined according to the development process, project management process, and the qualification process. The emphasis of this paper is on the so-called project view. Thereby the benefit of the SMW can be identified versus the conventional method. In order to be able to make a quantitative assessment, a set of criteria was defined. For each criterion, a figure of merit is given to quantify the impact. It allows the comparison of different development approaches, e.g., the SMW approach against the conventional IMA development approach. The assessment framework with the project view is applied to evaluate the SMW approach based on the experiences of a high-lift system development. Finally, the efficiency of the SMW is quantified and presented to estimate the approximate profit for the user.