Analyze requirements to ensure that they are necessary and sufficient.

In light of the operational concept and scenarios, the requirements for one level of the product hierarchy are analyzed to determine whether they are necessary and sufficient to meet the objectives of higher levels of the product hierarchy. The analyzed requirements then provide the basis for more detailed and precise requirements for lower levels of the product hierarchy.

As requirements are defined, their relationship to higher level requirements and the higher level defined functionality must be understood. One of the other actions is the determination of which key requirements will be used to track progress. For instance, the weight of a product or size of a software product may be monitored through development based on its risk.

Refer to the Verification process area for more information about verification methods that could be used to support this analysis.

Typical Work Products

1.    Requirements defects reports

2.    Proposed requirements changes to resolve defects

3.    Key requirements

4.    Technical performance measures

Subpractices

1.    Analyze stakeholder needs, expectations, constraints, and external interfaces to remove conflicts and to organize into related subjects.

2.    Analyze requirements to determine whether they satisfy the objectives of higher level requirements.

3.    Analyze requirements to ensure that they are complete, feasible, realizable, and verifiable.

While design determines the feasibility of a particular solution, this subpractice addresses knowing which requirements affect feasibility.

4.    Identify key requirements that have a strong influence on cost, schedule, functionality, risk, or performance.

5.    Identify technical performance measures that will be tracked during the development effort.

Refer to the Measurement and Analysis process area for more information about the use of measurements.

6.    Analyze operational concepts and scenarios to refine the customer needs, constraints, and interfaces and to discover new requirements.

This analysis may result in more detailed operational concepts and scenarios as well as supporting the derivation of new requirements.