Model Based Requirements Engineering in a digital-modeling environment provides advantages that document-based systems engineering cannot provide.
These advantages have led to increased and growing adoption since MBSE can save costs by reducing development time and improve the ability to produce secure and correctly functioning software.
Although various types of requirements can be represented in the model, there are three main types:
- Business requirements: High-level statements of the goals, objectives, or needs of an organization. They usually describe opportunities or problems that pertain to the organization.
- User requirements: Mid-level statements of the needs of a particular stakeholder or group of stakeholders. They usually describe how someone wants to interact with the intended solution. User requirements are often situated midway between the high-level business requirements and more detailed solution requirements.
- System requirements: Usually detailed statements of capabilities, behavior, and information that the solution will need including detailed statements of the conditions under which the solution must remain effective, qualities that the solution must have, or constraints within which it must operate. System requirements include non-functional requirements, often called quality attributes or “ilities,” such as security, usability, testability and modifiability.
MBSE with SysML offers the generic element type requirement, as well as subclasses: business requirement, usability requirement, functional requirement, performance requirement, interface requirement, physical requirement, and design constraint.
There are no strict rules on whether to use different types of requirements. All requirements can be modeled as a generic requirement type. Alternatively, sophisticated models can be created by using all offered types and even adding customized types.
A middle course would be to have a mix of business requirements, generic requirements with additional stereotypes, and other MBSE requirement types as needed. The stereotype element type comes to SysML from Unified Modeling Language (UML), and is one of three types of extensibility mechanisms in UML.
Want to learn more? Tonex offers Model Based Requirement Engineering, a 4-day course that introduces you to model based requirements engineering and management by providing various perspectives that shaped the fundamentals and principals of this technique.
Such perspectives consider each requirement one by one in regards to its definition, but then also give meaning to each requirement by positioning it into the proper “context.”
For more information, questions, comments, contact us.