A simulation-based approach to testing embedded software

A development process based on concurrent engineering is considered to be a powerful aid for shortening development periods of embedded systems. In such a process development of different technological parts are endeavoured to be carried out as parallel tasks. Extensive testing efforts are usually needed when integrating these parts into the final product, and there often are problems concerning availability of each part for integration. In particular, the integration of hardware and software is often a bottleneck. The objective of this thesis is to study how software testing of embedded systems can be made less dependent on hardware development, in order to effectively support concurrent engineering. We present a practical method for decreasing sequential dependencies between software testing and hardware development of embedded systems. The approach is based on simulating the target hardware, environment and operating system on the same workstation where software design takes place. We describe a tool developed for supporting the simulation-based testing process. The method and the tool are analysed in terms of a survey that deals with both commercial and experimental testing tools. Applicability of the simulation-based testing method and the tool have been evaluated by large industrial exploitation. Excellent results have been obtained. Product development periods have been reduced by several months. Majority of the logical software errors have been found and corrected before the integration of software and target hardware. Experiences from testing of embedded communication protocol software are presented as an example