Robust priority assignment for fixed priority real-time systems

Research output: Chapter in Book/Report/Conference proceedingConference contribution


This paper focuses on priority assignment for real-time systems using fixed priority scheduling. It introduces and defines the concept of a "robust" priority ordering: the most appropriate priority ordering to use in a system subject to variable amounts of additional interference from sources such as interrupts, operating system overheads, exception handling, cycle stealing, and task execution time overruns. The paper describes a Robust Priority Assignment algorithm that can find the robust priority ordering for a wide range of fixed priority system models and additional interference functions. Proofs are given for a number of interesting theorems about robust priority assignment, and the circumstances under which a "Deadline minus Jitter" monotonic partial ordering forms part of the robust ordering. The paper shows that "Deadline minus Jitter" monotonic priority ordering is the robust priority ordering for a specific class of system, and that this property holds essentially independent of the additional interference function.

Original languageEnglish
Title of host publicationRTSS 2007: 28th IEEE International Real-Time Systems Symposium, 2007
Place of PublicationLos Alamitos
Number of pages12
ISBN (Print)9780769530628
Publication statusPublished - Dec 2007
Event28th IEEE International Real-Time Systems Symposium - Tucson, Arizona, United States
Duration: 3 Dec 20076 Dec 2007


Conference28th IEEE International Real-Time Systems Symposium
Country/TerritoryUnited States
CityTucson, Arizona


  • real-time
  • scheduling
  • schedulability analysis
  • priority assignment
  • fixed priority

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