Our society is today extremely dependent oncomputers. Not only PCs and laptops, but also the myriad of computers embedded ineveryday things around us, such as vehicles, aircrafts, toys, and telephones. For many of these computers their correctness depends not onlyon the resultsof their computations, but also on the time at which the results are produced. Failure to produce a result within given timing boundaries may cause substantial economic losses, or evene ndanger humanlife. A worst-case execution time (WCET) analysis derives an upper estimate on the worst possible execution time of a computerprogram. Reliable WCET estimates are a foundation when it must be proven that an embedded system always will behave correctly,even in the most stressful situations. This book contains the dissertation of DrAndreas Ermedahl, a renowned researcher and WCET analysis expert. It presents a WCET tool architecture applicable to a wide spectrum of embedded computers and programs, together with suitable algorithms and data structures. The book should be of interest for anyone involved inembedded system development who wants a deeper understanding of the timing analysis process.