November 2008:
This month Triakis delivered the Virtual System Integration Laboratory (VSIL) simulator that it developed for Crane Aerospace's A330/A340 Doors & Slides Control System (DSCS) software development & verification effort. The DSCS is a safety-critical system and as such, its software was developed to the DO-178B Level A standard. Much of the software development, and all of the verification testing was performed in the purely virtual VSIL simulator. Crane was able to take full credit for SW verification testing in the VSIL environment without having to conduct formal verification on the avionics hardware, since Triakis qualified the VSIL according to the requirements of DO-178B. Using the path-coverage code instrumentation tool from the company LDRA, along with an innovative Triakis-developed companion preprocessor and VSIL adaptation, Crane was able to execute their instrumented code in the VSIL with no timing penalty. They thereby achieved full modified condition/decision coverage (MCDC) with one continuous run of their software during formal qualification testing.
The A330/A340 DSCS SW Verification test teams were diversely located on two continents and avoided the costs of test hardware because the Triakis VSIL's total environment simulation does not require the support of any lab test equipment, production avionics hardware, or dedicated-function simulators for verification test.
To our knowledge, no software defects have ever been reported by any airframe manufacturer receiving an avionics system whose software was verified in a Triakis VSIL.
