Requirements Tracing

Definition

Requirements tracing is a requirements engineering technique during which the requirements are mapped to parts of other work products and parts of other work products are mapped to the requirements.

Discussion

TBD

Objectives

The typical objectives of requirements tracing are to:

• Support the determinination of whether or not all stakeholder needs have been specified as analyzed requirements.
• Support the determination of whether or not the specified requirements does not unnecessarily exceed the needs of the stakeholders.
• Support the determinination of whether or not all requirements have been:
  • Fullfilled by part of the architecture.
  • Fullfilled by part of the design.
  • Implemented by parts of the implementation (e.g., data, hardware, or software components).
  • Tested by one or more system-level test cases.
• Support the determinination of whether or not the application, framework, or component implement no more than what is specified in the requirements (i.e., no gold plating).
• Help the change control board determine the impact of changing one or more requirements.
• Help the development organization determine the impact of application test failure on the application.
• Help the management team manage the scope of the endeavor.

Preconditions

Requirements tracing can typically begin when the following preconditions hold:

• The project team members have been adequately staffed and trained in the requirements tracing technique.

Completion Criteria

Requirements tracing is typically complete if the following postconditions hold:

Steps

During requirements tracing, the following producers typically perform the following steps in an iterative, incremental, parallel, and time-boxed manner:

• Requirements Team:
  • Trace stakeholder needs to features and features to stakeholder needs.
  • Trace stakeholder needs to requirements and requirements to stakeholder needs.
  • Trace features to requirements and requirements to features.
• Architecture Team:
  • Trace requirements to components and components to requirements.
  • Trace requirements to architectural mechanisms and architectural mechanisms to requirements.
• Software Development Team:
  • Trace requirements to classes and classes to requirements.
• Independent Test Team:
  • Trace requirements to system-level test cases and system-level test cases to requirements.

Work Products

Requirements tracing typically results in the following work products:

• System Requirements Specification.
• System Architecture Document.
• Test Cases.

Limitations

Requirements tracing is typically subject to the following limitations:

• TBD

Guidelines

• Requirements tracing can require a very large amount of effort to perform if no tools are used because of the large number of requirements to be traced and the large number of things to trace them to.
• Requirements do not map one-to-one from needs to features to use cases to architectural mechanisms/components to code to test cases (and back).