|This artifact captures the quality attributes and constraints that have system-wide scope. It also captures system-wide functional requirements.
This artifact is used for the following purposes:
- To describe the quality attributes of the system, and the constraints
that the design options must satisfy to deliver the business goals, objectives,
- To capture functional requirements that are not expressed as
- To negotiate between, and select from, competing design options
- To assess the sizing, cost, and viability of the proposed system
- To understand the service-level requirements for operational
management of the solution
system-wide requirements by a number of common themes or subcategories: the
areas of performance and capacity, availability, usability, security and privacy,
maintainability, manageability, and flexibility. See the supporting guidance
for a description of the recommended categorization approach.
each system-wide requirement, capture attributes such as the source and priority
of the requirements, as described by the associated requirements management
- When you document system-wide requirements, ensure that the needs
of all of the stakeholders are represented. In particular, include
the needs of those who are responsible for maintaining or supporting the system
after it is delivered.
- Typically, there are some overlaps and gray areas between system-wide
requirements and other requirements work products. For example, the
authorization behavior of a system can be specified as use cases or as statements
within system-wide requirements. The overall driving need is that no important
requirements are missed or duplicated, and that there is an agreed upon approach
for capturing and processing every type of requirement.
- System-wide requirements originate from many places. Documenting
the source of the requirement is particularly important when you separate
externally mandated requirements.
- Requirements are often thought of as "Qualitative" (specifying
a quality or desirable characteristic) versus "Quantitative" (specifying
a quantity). Qualitative requirements can sometimes be elaborated into quantitative
- A good quality requirement is one that you can verify, either
through testing or some other objective evaluation.
- You must evaluate system-wide requirements for cost, schedule
impact, and level of contribution to business goals. Based on your
evaluation, the system-wide requirements should be iteratively challenged,
defended, and amended.
|Impact of not having||
you do not adequately manage and meet system-wide requirements, you risk delivering
a system that might be unacceptable to stakeholders.
|Reasons for not needing||
You do not need to use this artifact if none of the categories of system-wide
requirements apply to the project under consideration.
artifact represents the influences on the design and delivery of a system,
which cover a broad range of themes. Document the requirements for each theme
under separate headings within a document or under appropriate category identifiers
in a requirements gathering tool. Give categories easy-to-recognize identifiers,
so individual requirements can be readily associated with the appropriate
category. The format of requirements vary from category to category; some
are heavily textual, and others are more structured and quantitative.