Control strategies for off-line testing of timed systems

TL;DR

This paper extends game-based test synthesis methods for timed automata, addressing partial control issues to generate sound and exhaustive test cases for timed systems.

Contribution

It introduces a new game interpretation for timed test synthesis, ensuring soundness and exhaustiveness under fairness assumptions.

Findings

Strategies minimize control losses and distance to test goals

Proven strategies are winning under fairness assumptions

Ensures soundness and exhaustiveness of test cases

Abstract

Partial observability and controllability are two well-known issues in test-case synthesis for interactive systems. We address the problem of partial control in the synthesis of test cases from timed-automata specifications. Building on the tioco timed testing framework, we extend a previous game interpretation of the test-synthesis problem from the untimed to the timed setting. This extension requires a deep reworking of the models, game interpretation and test-synthesis algorithms. We exhibit strategies of a game that tries to minimize both control losses and distance to the satisfaction of a test purpose, and prove they are winning under some fairness assumptions. This entails that when turning those strategies into test cases, we get properties such as soundness and exhaustiveness of the test synthesis method.