an empirical study of software reuse vs. defect-density and stability
The paper describes results of an empirical study,where some hypotheses about the impact of reuse ondefect-density and stability, and about the impact ofcomponent size on defects and defect-density in thecontext of reuse are assessed, using historical data ("datamining") on defects, modification rate, and software sizeof a large-scale telecom system developed by Ericsson.The analysis showed that reused components have lowerdefect-density than non-reused ones. Reused componentshave more defects with highest severity than the totaldistribution, but less defects after delivery, which showsthat that these are given higher priority to fix. There arean increasing number of defects with component size fornon-reused components, but not for reused components.Reused components were less modified (more stable) thannon-reused ones between successive releases, even ifreused components must incorporate evolvingrequirements from several application products. Thestudy furthermore revealed inconsistencies andweaknesses in the existing defect reporting system, byanalyzing data that was hardly treated systematicallybefore.
empirical studies software software reuse reuse stability paper component size data large-scale systems analysis priorities applications product