A Case Study: Application of the Systems Engineering Modeling in the early phases of a Complex Space System Project

There is increased recognition of the role of systems engineering in reducing the risk (technical, cost, and schedule) on complex space systems development and integration projects. A number of international systems engineering standards have been published in the last five years (ISO 15288, IEEE 1220, and EIA 632). Closer to the space domain, NASA recently updated and finalized the NASA Systems Engineering Processes and Requirements guidelines (NPR 7123.1 and NPR 7120.5). Figure 1 represents an encapsulated perspective on the key systems engineering processes and their dependencies are articulated in the new NASA NPR 7123.1. The NASA acquisition framework (Figure 2) represents their recursive (across levels) and iterative (within a level) approach to the SE process, and includes milestones and reviews, as well as updates to those events. This paper will focus on the early phases of the systems engineering process. This represents the first two System Design Processes of Figure 1, and the Pre-Systems Acquisition Phase – the Pre-Phase A, Phase A and Phase B in Figure 2. The paper will walk through a case study of a space system from the initial problem statement to defining the architectural technical risk to the program. The case study will show how early system engineering tools such as User Scenarios, Quality Function Deployment, and selection matrixes can be used in the initial system decisions to satisfy the NPR process. Then Systems Engineering Modeling will be illustrated in the context of a space systems case study [2]. Unique concepts such as active and passive stakeholders, and stakeholder capabilities and characteristics will be articulated to reduce the risk of misalignment between stakeholder expectations and technical system requirements. A framework for articulating a defined space mission into a set of well expressed and aligned technical requirements will be presented that satisfies the NPR process.