Supplementing Process-Oriented with Structure-Oriented Design Explanation within Formal Object Oriented Method

This paper reports the results from an action research project which studies the benefits of documenting the evolution and the rationale for the evolution of a requirements specification. Earlier research into the use of ad hoc design explanation, in which design decisions were documented using the IBIS notation (Issue Based Information System) as they were made, found both benefits and weaknesses of the approach. The weaknesses suggested an investigation into the complementary use of a post hoc notation--QOC (Question-Option-Criteria). This study was undertaken with a view to understanding the potential contribution of supplementing the IBIS approach with additional rationale reported using QOC. This study demonstrated that both notations were useful. The study resulted in a deeper understanding of the process of documenting the evolution of the requirements and the rationale for the evolution. The study also led to a few suggestions about how to use both the QOC and IBIS notations effectively.