Approach to systematic test signal definition for operation scenarios of aircraft systems
With rapidly increasing levels of automation, modern aircraft systems become increasingly complex. The designed solutions typically achieve multiple functions by using a highly integrated mix of hardware and software components. With regard to automation, particularly the number of software components increases. For verification and validation activities, such as testing, this intensifies the challenge to define all relevant scenarios to test a system's functionalities and particularly its robustness in the case of unusual, but realistic situations. Hidden failure cases might be missed. Additionally, it becomes infeasible to systematically define the test vectors to study a systems behavior thoroughly due to the immense test space. As a consequence, testing gets more work- and time-intensive. This paper presents a stepwise model-based method to define and refine the stimulating part of the test scenarios in a systematic and modular manner to approach this challenge. The aim is to work out diverse and relevant operational scenarios to validate system functions and to set up realistic test vectors for these scenarios. The paper further focuses on the aim to facilitate automation and re-usability of scenario and functional signal elements to enable continuous testing at different stages of the development process. Concepts of a developed prototype are outlined as well. Finally, the current state of the method is discussed and an overview of the way forward is given.