Bottoms up! Testing top-down software designs

摘要

Software development schedules are being stretched to the breaking point across the automotive industry, while quality requirements are skyrocketing. Improved specifications help in the development of quality software, but further steps are warranted. Software testing strategies are being examined across the industry, with special attention to the manner by which they fit into the software development process. This document presents one such strategy, with special emphasis on an often-overlooked step in software testing: the Unit Test. The cost to detect and fix a bug at the unit level is startlingly less than at higher levels of test. One reason for this is that unit test is generally the only level at which unusual and unexpected conditions are systematically tested. Untested unexpected conditions, when detected by the consumer, often result in emergency changes to the product, and can even cause a general recall upgrade. It is far more effective to test and debug these issues at the unit level before progressing to higher-level testing and eventual product release.