Engineering Strength Response-Time Analysis --- A Timing Analysis Approach for the Development of Real-Time Systems

When developing computer systems that are part of larger systems, as in control systems for cars, airplanes, or medical equipment, reliability and safety is of major concern. Developers of these systems want to keep the production and development costs to a minimum while maximizing customer benefit by increasing the functionality of the product. Increasing the number of functions, along with the added complexity that it entails, places a demand on better development methods, models, and tools. Response-Time Analysis (RTA) can be a useful method for these systems by able to guarantee a system’s temporal behavior. This thesis presents new techniques aimed at improving currently existing RTA methods. Specifically, these techniques lead to the following improvements: • The precision in the calculated response times are significantly higher than with previous methods, with typically 15% shorter response times. • The analysis, itself, can be made more 100 times faster than with previous implementations. By combining these independent techniques of precise (tight) response times and fast analysis, as shown in this thesis, one can get the benefits of both in a single analysis method. High precision response-time estimates enable either increased functionality within a given hardwaren cost, or a lower cost for a given functionality. Faster RTA will increase the usefulness of RTA by enabling the use of RTA in development tools for real-time systems with hundreds, or even thousands of tasks. RTA can be particularly beneficial for safety critical applications that have even higher requirements on reliability and safety, and often undergo expensive and lengthy certification processes. We illustrate the possible advantages by applying RTA for tasks with offsets in a real industrial context. The benefits consist of simplifying the development process as well as enabling an efficient resource usage.