In the frame of the ESA e.Deorbit study (Architecture Definition phase), a highly integrated and collaborative MBSE process related to Systems Modelling and Simulation has been developed and applied for supporting the iterative generation and maturation of the system requirements, architectures and system budgets at phase B1 level. e.Deorbit is a compelling mission concept that addresses the most pressing debris challenge for Europe: the post-life disposal of ESA’s environmental satellite Envisat. The e.Deorbit robotic-based chaser is characterized by strong safety (avoid collisions between chaser and target) and autonomy (capabilities to operate automatically with ground supervision) features. Additionally, the system complexity w.r.t.
1. the dependencies in and between the architectures,
2. the number of mission scenarios including the contingencies and
3. the system responses according to changes in the mission environment and the system configuration
calls for system modelling and simulation to support the proper definition of the mission and the system and architecture requirements.
During the e.Deorbit study, complemented with Airbus internal studies, a MBSE process called “Federated and Executable Models” was developed with further support of Phoenix Integration and RHEA. The main motivation of this approach is to maintain systems thinking aspects over the complete SE methodology.
MBSE patterns, data loops, data models and data sprints build the overall Systems Engineering (SE) process based on models, operability between the models and SE strategies. They produce together iteratively and successively the organization of the information leading to an optimal system definition for the system environment. They synthesize a unified whole, i.e. an open system with properties, capabilities and behaviours corresponding to the expected emergent properties, capabilities and behaviours. Using new standards for interoperability (OSLC, Linked Data) and high-end visualization technologies (VR) the MBSE toolchain is driving and fostering core characteristics of agile development tactics, such as improved collaboration and stakeholder interaction through transparency and communication. They provide a holistic, multi-disciplinary and collaborative approach to designing and maintaining complex systems.
Furthermore, this MBSE process strategy allows eliminating or mitigating the threads associated with a system definition. The architectural and design aspects in the requirements and vice versa are covered, consistent data for the different system analyses are used, the architectures are described in the same context reducing the risk to not catch the relevant relationships and the system complexity, and it is verified early in the process by simulation, whether the system fundamental properties are generated by the developed solutions.
This MBSE process is also considered as an industrial production means for system definition in studies and projects. The process might lead to a higher efficiency in the Systems Engineering work. The objective at Airbus Defence and Space is to iteratively implement and experiment this MBSE process.
W.r.t. the full MBSE process addressed in the paper, only a part of it related to architecture was implemented so far. The presented MBSE patterns and data models will need further definition and validation work in experiments before their full application in studies.