Metrics and laws of software evolution-the nineties view

TLDR

Software evolution is a complex multi‑input, multi‑output system with feedback at many levels, making improvement difficult; early observations from OS/360 and the FEAST hypothesis confirm this complexity. FEAST/1 aims to provide a foundation for mastering the feedback aspects of software evolution, enabling new process modeling and improvement. Preliminary analysis of Logica’s Fastwire confirms or does not contradict the laws of software evolution, supporting the continued relevance of 1970s metric analysis.

Abstract

The process of E-type software development and evolution has proven most difficult to improve, possibly due to the fact that the process is a multi-input, multi-output system involving feedback at many levels. This observation, first recorded in the early 1970s during an extended study of OS/360 evolution, was recently captured in a FEAST (Feedback, Evolution And Software Technology) hypothesis: a hypothesis being studied in on-going two-year project, FEAST/1. Preliminary conclusions based on a study of a financial transaction system-Logica's Fastwire (FW)-are outlined and compared with those reached during the earlier OS/360 study. The new analysis supports, or better does not contradict, the laws of software evolution, suggesting that the 1970s approach to metric analysis of software evolution is still relevant today. It is hoped that FEAST/1 will provide a foundation for mastering the feedback aspects of the software evolution process, opening up new paths for process modelling and improvement.