Application of Statistical Process Control to Software Defect Metrics: An Industry Experience Report

Statistical Process Control (SPC) has become of great significance for software engineering organizations as more of them decide to implement quality improvement initiatives. The Capability Maturity Model Integration (CMMI-DEV 1.3) for example, proposes the use of statistical techniques at maturity level 4 to ensure some degree of process predictability. However, the nature of software products and processes poses many challenges to the application of SPC, mainly regarding the design of control charts, a key tool. These challenges have led to opposing views on the applicability of SPC to software processes. This article presents an industry experience report on the application of SPC in a Software Verification and Validation Unit at an Information Technology Division from a financial institution. We present the steps followed to implement SPC in this organization, describe the theoretical assumptions involved in selecting the appropriate control charts, and show a process improvement analysis of using SPC in the organization.