A SE process model was developed, incorporating clear phases with iterative loops shown in Figure 13. This process model contains a logical progression that leads to a system recommendation at the end of the SE Process. The process begins with the initial tasking statement that was presented to the team. This tasking statement enters the main component of the process. This component consists of three main phases (Problem Exploration, System Definition, and Modeling & Analysis). Each of these three phases has three sub-phases connected by a rotational cycle. The output of one phase becomes the input to the next phase; however, an iterative loop back to the previous phase is also available as shown with the feedback arrow. This feedback allows continuous refinement the original problem, if needed. The dotted lines around the phases denote open information flow into each phase. The process model is not a closed-loop process, so discoveries at any phase can lead to refinements of any other phase.
Stakeholder Analysis Threat Scenario Analysis Problem Statement Development Requirement Analysis Current Capabilities Analysis Capabilities Gap Analysis System Refinement Modeling and Simulation Analysis of Results Problem Exploration
Modeling and Analysis System Definition FEEDBACK FEEDBACK INITIAL TASKING STATEMENT REQUIREMENTS COMPONENT SELECTION SYSTEM RECOMMENDATION Figure 13. SEA-20A revised systems engineering process diagram.
1. Problem Exploration Phase
The first step of the SEA-20A systems engineering process model was to analyze the initial tasking statement during the problem exploration phase. While exploring the problem given in the initial tasking statement and conducting applicable background research, the team looked at potential stakeholders and the influence each stakeholder might have on forming the initial problem statement. After identifying various stakeholders, the team performed a needs analysis. Threat scenario analysis was conducted to scope the problem, and three scenarios were created that were representative of potential threats. After investigating the background information on the problem, looking at particular problems presented by various threats, and exploring stakeholder groups, the initial problem statement was formed. As the understanding of the problem grew, each of the tasks within the problem exploration was revisited and traceability ensured back to the initial requirements. Major discoveries in the problem exploration phase include littoral operating environment challenges, operation in an A2AD environment, and specific needs analysis for potential stakeholders. The trade space analysis, which provides problem exploration phase background and system definition phase justification, is contained in Supplemental D.
2. System Definition Phase
After forming the initial requirements, the system definition phase of the SE process model was undertaken. During this phase, the team studied the causal relationship between stated requirements and capabilities of the small combatant ship. A rotational research cycle was conducted between capabilities and requirements to ensure the system definition was correctly understood and communicated through component selection. The rotational research cycle consisted of an iterative process in which system requirements were compared to current capabilities to identify capability gaps used to refine system requirements. This analysis refined the requirement for an effective surface-to-surface weapon and for a defensive network incorporating existing surface and air platforms to perform the sea denial mission. Boundaries discovered during this analysis included the engagement range, tonnage of each ship, draft, capability of
operating in an A2AD environment, and capability of operating with various types of units and assets. Some boundary conditions discovered during this analysis include relationships between cost and capability, size and seaworthiness, autonomy and interoperability.
The project was scoped to develop high-level system of systems design specifically capable of operating in an A2AD environment and a CONOPS for its employment. Results that are required from the modeling and analysis phase are system recommendations based on analysis of the engagements in the model. At this point in the SE process, the initial set of capabilities that helped develop the modeling and analysis phase of the project were defined.
3. Modeling and Analysis Phase
The modeling and analysis phase of the SE process is dependent on the component selection derived in the system definition phase. Evaluation of component selection was modeled and tests conducted to determine if the system of systems is effective based on the requirements defined in Chapter III Section C.5. After analyzing the results, system refinement was accomplished using iterative feedback paths to previous SE phases. In doing so, the refinement allowed tasks to be revisited and thus provide further insight and a better understanding of the problem. For example early discoveries in the modeling phase led to the requirement for a “system of systems” approach to defending the distributed surface force to survive in a multi-threat environment. Additionally, the need for an air defense platform was established and included in an iteration of the model. Finally, after iterations of the SE phases and sub- phase tasks, a system recommendation was determined as an output presented in Chapter VII. Major discoveries in this SE phase included the creation of a robust logistical network to meet fuel demand requirements to support missions that lasted more than 10 days and the need for off-ship sensor platforms to extend targeting range of surface combatants.