Front End Requirements Traceability for Small Systems

摘要

One of the most controversial topics software development practitioners debate is the area of requirements traceability. While there are some who question the value and the cost of requirements traceability in application development, most practitioners assert that effective traceability of requirements can lead to a higher quality application that is more likely to meet or exceed stakeholder expectations. Yet, for many the salient issue is exactly how do we effectively trace requirements that is both low in cost, high in value, and easy to implement? Simply put, how much effort is needed? What is an effective mechanism to support traceability? This paper presents a case study using experiences and data captured from a real application development undertaken by two teams of graduate software engineering students. These teams were charged with the specification, design, development, and implementation of a non-trivial medical information system envisioned to support a small medical clinic whose mission is to serve the working, medically un-insured in Jacksonville, Florida, a metropolitan community of about 1.2 million people. The Volunteers in Medicine (VIM) pro bono project was undertaken in response to a pressing need by this volunteer group. While the functional requirements were ever-changing, the non-functional requirements, as the VIM is staffed with almost all volunteers many of whom are senior citizens facing an automated system designed to replace accustomed hard copy record keeping, scheduling and reporting. Each team identified a single individual tasked with ensuring functional requirements traceability, which was part of each of the eleven deliverables. This successful approach uses forward and backward traceability matrices starting with careful elicitation and capture of Needs, the filtering of Needs to Features, and the elaboration of Features to Use Cases - all one to many relationships. Traceability was extended to include an Analysis Model. The paper discusses traceability beyond the analysis model extending into design. It is also pointed out that the traceability matrix approach can be readily applied to tracing features to non-functional requirements as well as tracing both functional and non-functional requirements to specific test scenarios.