Conference article

From the systems engineering standpoint, an aircraft may be considered a complex system consisting of multiple subsystems operating in an integrated manner, within several operational environments. During the operation, deviations from the design may arise due to the interaction among the aircraft subsystems and their environments. Such deviations require the aircraft manufacturer to redesign a subsystem in order to obtain a solution of high effectiveness and avoid additional costs of a second rework. This paper presents a requirements engineering-based approach to define or modify a process in which an aircraft subsystem is redesigned. The approach is comprised of seven steps, which include the stakeholder, functional and physical analyses previously presented in the total view framework. The proposed activities also include defining the measures of effectiveness (MoEs), as well as a validation and verification (V&V) strategy for both the system and the requirements. The present work highlights the importance of requirements definition and management during a modification that occurs at an advanced life cycle stage. The steps presented may be seen as guidelines either to modify or define a process. Therefore, the way each step is deployed depends upon the complexity of the system and organizational issues. A case study has been carried out to evidence the performance difference between a system modification process currently used at an aerospace company and the process modified with the approach presented herein. The outcome shows that the new process would potentially reduce the previously found problems by around 60%, and it is believed that this figure would be even greater if the process were actually implemented.

systems modification, requirements engineering, complex systems