Technical Reports

Commercial-Off-The-Shelf (COTS) Hardware and Software for Train Control Applications: System Safety Considerations

  • 01
  • Apr
  • 2003
AUTHOR: Federal Railroad Administration
KEYWORDS: commercial off-the-shelf (COTS); operating system; positive train control; modified off-the-shelf (MOTS)
ABSTRACT: The objective of this study was to assess the feasibility of using commercial off-the-shelf (COTS) processor-based systems for safety-related railroad applications. From the safety perspective, the fundamental challenges of using COTS products are most pronounced within the product evaluation and safety assurance phases of the traditional development life cycle. Even in the case of COTS components that can be considered commodities, such as certain microprocessors and operating systems, there are some necessary life cycle modifications. First, more iteration at the system level is required to accommodate component evaluation and selection as well as deal with technical and business requirements and tradeoffs. Second, the entire development life cycle has to be modified to address realities such as component evaluation and the high pace of change in the commercial market of today. To address these realities, an iterative life cycle was proposed for systems incorporating COTS components. Finally, traditional safety verification and validation methodologies were contrasted with safety validation approaches for integrating COTS components into hardware and software systems. This effort resulted in a structure to support the development of a system safety program plan for COTS operating system platforms executing safety-critical applications.