Defensive Approaches to Testing Systems that Contain COTS and Third-Party Functionality

Most systems today are composed of hardware components, COTS software, and custom software. When a system fails, a confusing and complex liability problem ensues for all parties that have contributed software and hardware functionality to the composite system. This paper presents a consumer-oriented methodology for predicting what impact on system quality a particular Commercial-Off-The-Shelf (COTS) software component will have. When the result computed by the custom software causes a system failure, it becomes necessary to track down why that result occurred. If it is because of a logical defect in the custom software, then the vendor of the custom software is liable. If the result occurred because of a failure of a COTS software component (upon which the custom software was dependent for information), then the COTS vendor should be liable. Regardless of how these events might get argued in a court case and who would prevail, those persons responsible for integrating custom and COTS software together should take pro-active steps to ensure that all safeguards against COTS software failures have been taken. That is clearly their best legal defense strategy. This paper presents methods that provide those safeguards.