Test Plan Generation for Concurrent Real-Time Systems Based on Zone Coverage Analysis

The state space explosion due to concurrency and timing constraints of concurrent real-time systems (CRTS) presents significant challenges to the verification engineers. In this paper, we investigate how to use coverage techniques to generate efficient test plans for such systems. We first discuss how to use communicating timed automata to model CRTS. We present a new coverage technique, AZC (active zone coverage), based on the zone equivalence relation between states of CRTS. We discuss techniques to estimate AZC values of active zones represented in BDD-like diagrams. We explain how to construct zone trees and map their root-to-leaf paths to test cases. We then present an algorithm to generate test plans by prioritizing the test cases. The test plans that we generate can efficiently achieve full coverage in AZC. We have implemented our ideas with our TCTL model-checker RED. Experiment report with the Bluetooth L2CAP showed improvement of the coverage growth rate in the test plan execution.