A SOFTWARE FAULT PREVENTION APPROACH IN CODING AND ROOT CAUSE ANALYSIS

The complexity of Lucent Technologies' advanced 5ESS(R) switching syst em makes the cost of finding, fixing, and retesting a software fault v ery high. The current 5ESS system contains several million lines of so urce code, which provide many complicated real-time switching function features. As customer demands for ever-increasing product quality com pound the high cost of testing and reworking source code, it is crucia l for the SESS Switching Development organization to find ways to prev ent faults from being introduced into the software in the first place. The 5ESS Switch Coding Fault Prevention Team was assembled to find me thods to prevent the most frequent faults from being injected into a p roduct during coding. The Coding Fault Prevention Guidelines, develope d by the team for use in various Lucent switching development organiza tions, lists the most frequent errors made during coding. if also prov ides coders with information that will help reduce the risk of introdu cing faults into the software. This paper describes the most common pr eventable faults and the technical guidelines developed to overcome th em, it also explains the metrics used to evaluate the results achieved .