A Hybrid between Model-Based Systems Engineering and Agile Methodologies for Simulation of Complex Weapon Systems of Systems

Modern Aerospace and Defence capabilities are “Systems of Systems” (SoS) by design, which has resulted in the development of a range of new systems engineering techniques in order to address the challenges introduced by this complexity. The use of modelling and simulation for ongoing analysis forms the backbone of various SoS Engineering (SoSE) methodologies, and many of the challenges that arise in SoSE apply equally to the modelling, simulation and analysis of complex integrated systems. Weapons and Combat Systems Division, in collaboration with other Australian Department of Defence agencies, is developing a modelling, simulation and analysis capability in order to investigate the performance of integrated defence systems. The execution of this development is being undertaken in the form of a “study series” based on the SoSE Wave Model and is composed of discrete sub-studies. Each of these sub-studies is used to progressively increase the complexity of the scenario being modelled (both number of systems being modelled and model fidelity) whilst performing analysis and answering questions for Defence stakeholders. This approach ensures regular and ongoing feedback and investment from client groups, and that the final modelling and simulation capability is fit-for-purpose to meet the strategic objectives. The study series operates on a yearly cycle of analysis where traditional model-based systems engineering (MBSE) approaches are employed to support the analytical and top-level model requirements definition. However, the developers of the various software models used within the study series commonly apply Agile-based methodologies, in accordance with current software engineering best practice. A hybrid methodology has been developed to manage this, incorporating components of more traditional MBSE tools and techniques at the study level, and Agile methodologies for model development. This paper describes this hybrid methodology, including how MBSE is utilised to manage an evolving, complex, SoS simulation capability, define study requirements, and integrate with an Agile software model development approach. The paper employs an unclassified aerospace example in which modelling and simulation-based analyses have been applied to explore how different Uninhabited Aerial System concepts could be implemented in concert with other platforms to enhance an Anti-Ship Missile Defence capability. The requirements definition approaches are explored from both the analysts' and model developers' perspectives.