• Medientyp: E-Artikel
  • Titel: Dealing with Uncertainty in pWCET Estimations
  • Beteiligte: Reghenzani, Federico; Santinelli, Luca; Fornaciari, William
  • Erschienen: Association for Computing Machinery (ACM), 2020
  • Erschienen in: ACM Transactions on Embedded Computing Systems, 19 (2020) 5, Seite 1-23
  • Sprache: Englisch
  • DOI: 10.1145/3396234
  • ISSN: 1539-9087; 1558-3465
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  • Beschreibung: The problem of estimating a tight and safe Worst-Case Execution Time (WCET), needed for certification in safety-critical environment, is a challenging problem for modern embedded systems. A possible solution proposed in past years is to exploit statistical tools to obtain a probability distribution of the WCET. These probabilistic real-time analyses for WCET are, however, subject to errors, even when all the applicability hypotheses are satisfied and verified. This is caused by the uncertainties of the probabilistic-WCET distribution estimator. This article aims at improving the measurement-based probabilistic timing analysis approach providing some techniques to analyze and deal with such uncertainties. The so-called region of acceptance model based on state-of-the-art statistical test procedures is defined over the distribution space parameters. From this model, a set of strategies is derived and discussed to provide the methodology to deal with the trade-off safety/tightness of the WCET estimation. These techniques are then tested over real datasets, including industrial safety-critical applications, to show the increased value of using the proposed approach in probabilistic WCET analyses.