Artifact: Software Requirements
Specification
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The Software Requirements Specification (SRS) captures the software requirements for the complete system, or a portion of that system. |
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| Role: | Requirements Specifier |
| Optionality/Occurrence: | Considered first in the Inception phase, refined in the Elaboration and Construction phases. |
| Templates and Reports: | |
| Examples: |
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| UML Representation: | Not applicable. |
| More Information: |
| Input to Activities: | Output from Activities: |
Purpose 
The Software Requirements Specification (SRS) focuses on the collection and organization of all requirements surrounding your project. Refer to the Requirements Management Plan to determine the correct location and organization of the requirements. For example, it may be desired to have a separate SRS to describe the complete software requirements for each feature in a particular release of the product. This may include several use cases from the system use-case model, to describe the functional requirements of this feature, along with the relevant set of detailed requirements in Supplementary Specifications. The Software Requirements Specification is useful for collecting your project software requirements in a formal, IEEE830-style document.
Since you might find yourself with several different tools for collecting these
requirements, it is important to realize that the collection of requirements
may be found in several different artifacts and tools. For
example, you might find it appropriate to collect textual requirements such
as non-functional requirements, design constraints and so forth, with a text
documenting tool in Supplementary Specifications.
On the other hand, you might find it useful to collect some (or all) of the
functional requirements in the use cases and you might
find it handy to use a tool appropriate to the needs of defining the use-case
model. For this reason, we will collect the requirements for our SRS
in a package which may be a single document or a collection of various artifacts
that describe the requirements.
(See the More Information section for additional guidelines).
The SRS package controls the evolution of the system throughout the development phase of the project, as new features are added or modified to the Vision document, they are elaborated within the SRS Package. The following people use the Software Requirements Specification:
- The system analyst creates and maintains the Vision and Supplementary Specifications, which serves as input to the SRS and are the communication medium between the system analyst, the customer, and other developers.
- The requirements specifier creates and maintains the individual use case and other components of the SRS package,
- Designers use the SRS Package as a reference when defining responsibilities, operations, and attributes on classes, and when adjusting classes to the implementation environment.
- Implementers refer to the SRS Package for input when implementing classes.
- The Project Manager refers to the SRS Package for input when planning iterations.
- Testers use the SRS Package as an input to considering what tests will be required.
Brief Outline
The Software Requirements Specification (SRS) captures the complete software requirements for the system, or a portion of the system.
Many different arrangements of an SRS are possible. Review the tailoring section for additional guidance.
Timing
Software Requirements Specification:
- Are initially considered in the Inception phase, as a complement to defining the scope of the system.
- Are refined in an incremental fashion during the Elaboration and Construction phases.
Responsibility
A Requirements Specifier is responsible for producing the Software Requirements Specification (SRS) package, which is an important complement to the use-case model. The SRS Package collects applicable Supplementary Specifications and use cases of the use-case model which together capture a complete set of requirements on the system or a defined subsystem .
Tailoring
Many different arrangements of an SRS are possible. Review the templates and examples section in the header table of this page for arrangements relevent in your project context. Refer to [IE830] for further elaboration of this artifact, including other options for SRS organization.
This artifact logically encloses the following:
