SRC Ratio Method: Benchmarking Software Reliability
Pete Rotella, Sunita Chulani · 2017
Software Reliability Classes (SRCs) have been developed in order to compare the field reliability performance of a sequence of software releases for a cluster of similar hardware products. A specific cluster is characterized by the type of market the hardware supports, and the software releases for the cluster have similar functionality, complexity, size, and customer expectations. SRCs are a normalized form of an already normalized customer experience metric, 'software defects (encounters) per million usage hours' referred to as SWDPMH. Different hardware devices, even though running identical software, can experience up to three orders of magnitude variation in SWDPMH values. The SRC method enables us to compare the best-in-class SWDPMH value, for each cluster, to the current field SWDPMH value, and this enables us to use the same SRC ratio calculation across all reliability classes to assess the reliability health of all software releases. The overall reliability health of a business unit's software, for all hardware devices supported, can thereby be accurately calculated, trended, and goaled, with particular attention paid to improving release-over-release reliability.