One of the fundamental concepts used within NASA for the management of major systems is the program/project life cycle, which consists of a categorization of everything that should be done to accomplish a program or project into distinct phases, separated by Key Decision Points (KDPs). KDPs are the events at which the decision authority determines the readiness of a program/project to progress to the next phase of the life cycle (or to the next KDP). Phase boundaries are defined so that they provide more or less natural points for Go or No?Go decisions. Decisions to proceed may be qualified by liens that must be removed within an agreed to time period. A program or project that fails to pass a KDP may be allowed to “go back to the drawing board” to try again later—or it may be terminated. The most dramatic impacts of the analysis and optimization activities associated with systems engineering are obtained in the early stages. Decomposing the program/project life cycle into phases organizes the entire process into more manageable pieces.

The program Formulation phase establishes a cost-effective program that is demonstrably capable of meeting Agency and mission directorate goals and objectives. The program Formulation Authorization Document (FAD) authorizes a Program Manager (PM) to initiate the planning of a new program and to perform the analyses required to formulate a sound program plan.

Project Pre-Phase A: (Concept Studies) is usually performed more or less continually by concept study groups, with the purpose to devise various feasible concepts from which new projects (programs) can be selected. Typically, this activity consists of loosely structured examinations of new ideas, usually without central control and mostly oriented toward small studies. Advanced studies may extend for several years and may be a sequence of papers that are only loosely connected.

During Phase A (Concept and Technology Development), activities are performed to fully develop a baseline mission concept and begin or assume responsibility for the development of needed technologies. The team’s effort focuses on analyzing mission requirements and establishing a mission architecture. Goals and objectives are solidified, and the project develops more definition in the system requirements, top-level system architecture, and ConOps. Conceptual designs are developed and exhibit more engineering detail than in advanced studies. Technical risks are identified
in more detail, and technology development needs become focused.

During Phase B (Preliminary Design and Technology Completion), activities are performed to establish an initial project baseline, which includes “a formal flow down of the project-level performance requirements to a complete set of system and subsystem design specifications for both flight and ground elements” and “corresponding preliminary designs.” The Phase B baseline consists of a collection of evolving baselines covering technical and business
aspects of the project: system (and subsystem) requirements and specifications, designs, verification and operations plans, and so on in the technical portion of the baseline, and schedules, cost projections, and management plans in the business portion. In Phase B, the effort shifts to establishing a functionally complete preliminary design solution (i.e., a functional baseline) that meets mission goals and objectives.

During Phase C (Final Design and Fabrication) activities are performed to establish a complete design (allocated baseline), fabricate or produce hardware, and code software in preparation for integration and tested to establish confidence that the design will function in the expected environments. Engineering test units more closely resembling actual hardware are built. During this phase, technical parameters, schedules, and budgets are closely tracked to ensure that undesirable trends are recognized early enough to take corrective action.

During Phase D (System Assembly, Integration and Test, Launch), activities are performed to assemble, integrate, test, and launch the system. Although all these activities are conducted in this phase of a project, the planning for these activities was initiated in Phase A. Phase D concludes with a system that has been shown to be capable of accomplishing the purpose for which it was created.

During Phase E (Operations and Sustainment), activities are performed to conduct the prime mission and meet the initially identified need and maintain support for that need. The products of the phase are the results of the mission.

During Phase F (Closeout), activities are performed to implement the systems decommissioning disposal planning and analyze any returned data and samples. The products of the phase are the results of the mission. Phase F deals with the final closeout of the system when it has completed its mission; the time at which this occurs depends on many factors. In addition to uncertainty as to when this part of the phase begins, the activities associated with safe closeout of a system may be long and complex and may affect the system design.

With annual funding, there is an implicit funding control gate at the beginning of every fiscal year. While these gates place planning requirements on the project and can make significant replanning necessary, they are not part of an orderly systems engineering process. Rather, they constitute one of the sources of uncertainty that affect project risks, and they are essential to consider in project planning.