Developing Software for Ease of Change: Metrics from Later in the TRALAB SystemLife Cycle

摘要

This paper is a summary of software change and defect data collected duringextended development and post-deployment software support (PDSS) for the Training Laboratory (TRALAB), a computer-based training system developed starting in 1984 by the Naval Center for Space Technology (NCST) at the Naval Research Laboratory (NRL). Of note, the development contractor was required to apply software engineering technology developed previously at NRL as part of the Software Cost Reduction (SCR) project. Another important requirement was for the collection of project metric data that could be used to evaluate the effectiveness of the SCR approach. Data collection was accomplished by modifying customary project Software Problem Reports (SPRs). Analysis of the data collected on SPR resolution work during extended development integration and test (IT) during August 1988 through April 1989 indicates that the application of SCR technology enhanced software ease of change. This paper is a continuation of the earlier analysis to include PDSS SPR data collected during August 1990 through May 1991. The more recent analysis continues to suggest that identifying expected system changes during system definition stages and modularizing the system to encapsulate these changes yield life-cycle benefits. Modifications required by changes tend to be confined to a small number of design components, and it is easier to implement expected changes in comparison to arbitrary changes. Computer programs, Ease of change, Information hiding, Software, PDSS, SCR, Metrics, TRALAB.