An Improved Operational Sequence Diagram Methodology for Use in System Development

Abstract

Operational sequence diagrams (OSDs) have been used to support human engineering in system development for decades (Kurke, 1961); however, due to variations in application domains, OSDs have had varying degrees of success in defining the critical aspects of system operation necessary for human-centered designs. One of the more significant evolutions to this method in recent years was a tailoring of the technique to be more easily used and interpreted by subject matter experts (SMEs) and engineers (Wallace, Bohan, and Perry, 1997). This format also emphasized a tighter coupling of “information requirements” as a design determinant to be tracked. Since then, this particular OSD methodology has been applied to a variety of programs and been used to support early system requirements reviews. Understandably, the wider use of this methodology has enabled its users to learn of shortcomings in different applications. This paper discusses additional enhancements to the visual representation of OSD methodology currently employed. This effort included the generation of requirements for an OSD method, interviews with previous and current generators and consumers of the OSDs, and evaluation of proposed improvements. Revised symbology and definitions required to use this improved methodology are discussed.