Compositional timing analysis

Computing the worst-case execution time (WCET) of real-time tasks is mandatory for the correct functioning of real-time systems. In component-based development (CBD) of real-time embedded systems, a task is typically constructed by composing appropriate software components together. Finding the WCET of a component-constructed task reduces to finding the WCETs of its constituent components and composing them in an appropriate fashion. In this paper we describe a method based on constraint-logic programming (CLP) to produce WCET estimates of real-time tasks where the components´ WCETs are expressed paramet-rically. The experimental results show that the derived WCETs using our approach benefit from an increased tightness while the practical (time) complexity of the approach is manageable.