The winning entry of the SAM 2002 design contest: A case study of the effectiveness of SDL and MSC

Abstract

The SDL Forum Society holds workshops on the languages SDL (Specification and Description Language) and MSC (Message Sequence Charts). At the 2002 workshop (SAM2002), held at Aberystwyth, Wales, an SDL design contest was held to promote discussion about the use of SDL. The contest challenge was to use SDL and MSC to specify a railway crossing system. Our team from the University of Ottawa, consisting of Qing Li, Alan Williams, Robert Probert and Tae-Hyong Kim won the contest. In this paper, we outline our design approach including requirements analysis, high-level design, iterative design construction, design verification, design validation against high-yield scenarios, and design maintenance based on new and changed requirements which arrived close to the end of the design cycle. We also describe the rationale for some of the decisions we had to make during the process. Based on our experience, we provide some comments on the strengths and weaknesses of the methods and tools that we used.