Experience of applying statistical control techniques to the function test phase of a large telecommunications system

The software test process of a large telecommunications system is presented. The feasibility of introducing statistical process control techniques to one crucial software test phase, namely the function test is explored. This phase has been identified as a strategic one for meeting the commitments to customers with respect to quality objectives. Analysis of past released products revealed that a high percentage of the failures experienced in operation corresponded to software faults that could have been discovered during the function test phase. A brief description of the statistical estimators investigated (Classical vs. Bayesian) is provided, along with a few examples of their use over real sets of data. Far from being aimed at identifying new statistical models, the focus of this work is rather about putting measurement in practice: easy and effective steps to improve the status of control over the test process in a smooth, bottom-up approach are suggested