Automated test-data generation for exception conditions

This paper presents a technique for automatically generating test-data to t est exceptions. The approach is based on the application of a dynamic globa l optimization based search for the required test-data. The authors' work h as focused on test-data generation for safety-critical systems. Such system s must be free from anomalous and uncontrolled behaviour. Typically, it is easier to prove the absence of any exceptions than proving that the excepti on handling is safe. A process for integrating automated testing with excep tion freeness proofs is presented as a way forward for tackling the special needs of safety critical systems. The results of a number of simple case-s tudies are presented and show the technique to be effective. The major resu lt shows the application of the technique to a commercial aircraft engine c ontroller system as part of a proof of exception freeness, This illustrates how automated testing can be effectively integrated into a formal safety-c ritical process to reduce costs and add value. Copyright (C) 2000 John Wile y & Sons, Ltd.