Establish and maintain operational concepts and associated scenarios.

A scenario is typically a sequence of events that may occur in the development, use, or sustainment of the product, which is used to make explicit some of the functional or quality attribute needs of the stakeholders. In contrast, an operational concept for a product usually depends on both the design solution and the scenario. For example, the operational concept for a satellite based communications product is quite different from one based on landlines. Since the alternative solutions have not usually been defined when preparing the initial operational concepts, conceptual solutions are developed for use when analyzing the requirements. The operational concepts are refined as solution decisions are made and lower level detailed requirements are developed.

Just as a design decision for a product can become a requirement for a product component, the operational concept can become the scenarios (requirements) for product components. Operational concepts and scenarios are evolved to facilitate the selection of product component solutions that, when implemented, will satisfy the intended use of the product or facilitate its development and sustainment. Operational concepts and scenarios document the interaction of the product components with the environment, end users, and other product components, regardless of engineering discipline. They should be documented for all modes and states within operations, product development, deployment, delivery, support (including maintenance and sustainment), training, and disposal.

Scenarios can be developed to address operational, sustainment, development, or other event sequences.

Example Work Products

1.    Operational concept

2.    Product or product component development, installation, operational, maintenance, and support concepts

3.    Disposal concepts

4.    Use cases

5.    Timeline scenarios

6.    New requirements

Subpractices

1.    Develop operational concepts and scenarios that include operations, installation, development, maintenance, support, and disposal as appropriate.

Identify and develop scenarios, consistent with the level of detail in the stakeholder needs, expectations, and constraints in which the proposed product or product component is expected to operate.

Augment scenarios with quality attribute considerations for the functions (or other logical entities) described in the scenario.

2.    Define the environment in which the product or product component will operate, including boundaries and constraints.

3.    Review operational concepts and scenarios to refine and discover requirements.

Operational concept and scenario development is an iterative process. The reviews should be held periodically to ensure that they agree with the requirements. The review can be in the form of a walkthrough.

4.    Develop a detailed operational concept, as products and product components are selected, that defines the interaction of the product, the end user, and the environment, and that satisfies the operational, maintenance, support, and disposal needs.