Employing use-cases and domain knowledge for comprehending resource usage-experience report

Philips Electronics is a world wide electronics company that develops many products containing embedded software. These products range from shavers with only a few hundred bytes of software to medical equipment with millions of lines of source code. Large systems are subject to successive changes during several years, which diminishes understanding. Furthermore, due to the cost reduction of a system in an industrial setting, design decisions are often made in favor of using less resources instead of writing comprehensive code. The paper addresses understanding the run time behavior, or more specifically, the resource usage of complex computer based systems. In order to obtain insight into the resource usage, the system under investigation is subjected to use cases ("Select"), during which the system is probed ("Measure") for resource usage data. The data is combined with domain knowledge which results in a resource usage model ("Analyze"). These three steps are referred to as the SMA steps. In the daily Philips practice, the SMA steps appear useful to form a basic understanding of the run time behavior of a system. The approach appears applicable in a wide range of settings: from a brief but quick analysis to a thorough but lengthy one.