Item Integrationand Testing
Item integration testing of the control software is performed in diverse ways at Pi. Software unit tests are the most common activity, utilizing the OpenECU Simulink Developer Platform toolchain, and unit test wrapper environments developed and maintained internally by Pi. According to the project requirements, lower-level verification such as code branch and statement coverage may be performed, using specialized analysis tools. Higher-level software verification is performed on-ECU, using plant-model-based HIL equipment, or other benchtop hardware devices developed for this testing. On-vehicle integration tests then follow later in the project, according to test plans that are reviewed, tracked, and managed according to Pi’s engineering processes.
Item Integration Testing Plan (IITP)
For ISO 26262 projects, an IITP is a Part 4 work product. For non-26262 programs, Pi Innovo refers to this as a test strategy. An integration test plan/strategy is based on the system design specification, the functional safety concept and the technical safety concept. Refined versions of the IITP call out the test methods that will be used for the following three levels of integration:
• Hardware Software Integration tests
• System Integration tests
• Vehicle Integration tests
Item Integration Test Specification
The item integration test specification is also an ISO 26262 Part 4 work product. For non-26262 applications this is essentially the test procedure. It contains the detailed procedures and test scripts that need to be executed for each test called out in the IITP.
An attempt is made to automate the test execution as much as possible with the exception of a few tests that need manual intervention. Pi uses a HIL system with scripting interfaces to perform a subset of this testing. Upon successful execution of the item integration test specification, the controller under test is considered validated and verified.