A survey-based study of the mapping of system properties to ISO/IEC 9126 maintainability characteristics

The ISO/IEC 9126 international standard for software product quality is a widely accepted reference for terminology regarding the multi-faceted concept of software product quality. Based on this standard, the Software Improvement Group has developed a pragmatic approach for measuring technical quality of software products. This quality model introduces another level below the hierarchy defined by ISO/IEC 9126, which consists of system properties such as volume, duplication, unit complexity and others. A mapping between system properties and ISO/IEC 9126 characteristics is defined in a binary fashion: a property either influences a characteristic or not. This mapping embodies consensus among three experts based, in an informal way, on their experience in software quality assessment. We have conducted a survey-based experiment to study the mapping between system properties and quality characteristics. We used the Analytic Hierarchy Process as a formally structured method to elicit the relative importance of system properties and quality characteristics from a group of 22 software quality experts. We analyzed the results of the experiment with two objectives: (i) to validate the original binary mapping and (ii) to refine the mapping using the elicited relative weights.