• Obsolete and nonrelevant systems engineering processes: a discussion warning against the use of legacy processes and guidelines that do not add value to the tasks at hand;

  • General processes and practices for systems engineering: a discussion of some of the processes that are critical after Milestone B, including modeling and simulation, control of lower-level requirements, and change control; and

  • A checklist: some of the committee’s most important findings, provided to guide systems engineering activities and output before Milestone B.


The prerequisite for starting the systems engineering process is a user-defined need (or outcome). The purpose of systems engineering in this phase is to define an optimal system concept and concept of operations (CONOPS) that satisfies the need and also fits within budgetary constraints. The systems engineering outputs in this phase include a concise statement of key performance parameters (KPPs), a CONOPS description, a program implementation strategy, and models to support performance assessment, cost estimation, and risk management in subsequent phases.

These functions are aggregated in the following broad areas, shown in Figure 4-1: concept creation, preliminary CONOPS, performance assessment, architecture development, risk assessment, and cost scoping. These functions are reiterative and thus occur in parallel, to produce the key outputs from the pre-Milestone A systems engineering process: KPPs, CONOPS, supporting models, and program implementation strategy.

FIGURE 4-1 Critical pre-Milestone A systems engineering functions and outputs. NOTE: CONOPS, concept of operations.

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