NAS Systems Engineering Manual- Perform Systems Engineering

4.1.2.9.2 Definition
Analysis is defined as a logical examination or study of a system to determine the nature, relationships, and interaction of its parts and environment. Integrity of Analyses is defined as a disciplined process applied throughout a program to ensure that analyses provide the required levels of fidelity, accuracy, and confirmed results in a timely
manner.

4.1.2.9.3 Value
Analyses are constantly being performed throughout SE and the program's lifecycle. These analyses range from simple to complex, quantitative to qualitative, top-down to bottom-up, and basic formulas to sophisticated simulations. To ensure credible, useful, sufficient, and timely data/results for program and/or technical decisions, the integrity and fidelity of the various analysis tools shall be understood and validated. This validation takes several forms: the attributes of the tool suite, validity of the input data, and proficiency and workmanship of the analyst. An Analysis Management Plan is generated that outlines the details of the various analysis methods and tools. It is recommended that this plan also reflect the program’s constraints regarding technical capabilities, schedule requirements, and cost requirements. The initial selection of the method, tools, or model to be used in an analysis focuses on determining a practical tool that provides the most visibility into the problem with the least complexity. Because this process is iterative, there is an ongoing need to use the best approach to select the right method, tool, or model, considering the preferences of the stakeholders, other teams’ previous experience with different tools, and the limitations of budgets, technology, and schedule. The bottom line is to have analyses in place that guard against mistakes and embed a consistent level of confidence in the integrity of the analysis. The analysis, in turn, contributes significantly to the success of the decision-making processes of program management, teams, stakeholders, and contract managers.