Priority Ranked Inspection: Supporting Effective Inspection in Resource-limited Organizations

Abstract

Imagine that your project manager has budgeted 200 person-hours for the next month to inspect newly created source code. Unfortunately, in order to inspect all of the documents adequately, you estimate that it will take 400 person-hours. However, your manager refuses to increase the budgeted resources for the inspections. How do you decide which documents to inspect and which documents to skip? Unfortunately, the classic definition of inspection does not provide any advice on how to handle this situation. For example, the notion of entry criteria used in Software Inspection determines when documents are ready for inspection rather than if it is needed at all. My research has investigated how to prioritize inspection resources and apply them to areas of the system that need them more. It is commonly assumed that defects are not uniformly distributed across all documents in a system, a relatively small subset of a system accounts for a relatively large proportion of defects. If inspection resources are limited, then it will be more effective to identify and inspect the defect-prone areas. To accomplish this research, I have created an inspection process called Priority Ranked Inspection (PRI). PRI uses software product and development process measures to distinguish documents that are "more in need of inspection" (MINI) from those ``less in need of inspection'' (LINI). Some of the product and process measures include: user-reported defects, unit test coverage, active time, and number of changes. I hypothesize that the inspection of MINI documents will generate more defects with a higher severity than inspecting LINI documents. My research employed a very simple exploratory study, which includes inspecting MINI and LINI software code and checking to see if MINI code inspections generate more defects than LINI code inspections. The results of the study provide supporting evidence that MINI documents do contain more high-severity defects than LINI documents. In addition, there is some evidence that PRI can provide developers with more information to help determine what documents they should select for inspection.