COTS product selection for safety-critical systems

There is an increasing interest in acquiring commercial-off-the-shelf (COTS) functionality for safety-critical applications. However, the selection of COTS products for such applications is still carried out in an ad hoc manner. This creates great difficulties for realistic cost and effort estimation, integration of the selected COTS product, and the certification of final COTS-based safety-critical systems. We believe that selection of an appropriate COTS product is the vital first step towards a successful COTS-based solution, especially for safety-critical applications. In this paper, we propose a pragmatic COTS selection approach in order to alleviate the perceived difficulties by providing a safety-informed decision on COTS selection. Reasoning from the perspective of the application context and application-specific hazards, the proposed approach defines a COTS acquisition contract from the safety requirements derived for the required COTS functionality. The terms of the COTS acquisition contract act as the evaluation and selection criteria against which any COTS candidates must be evaluated thus providing informed decisions on COTS selection for safety-critical applications.