Requirements traceability refers to the ability to track a requirement from its origin through its development and specification in design and implementation, and onwards into its final deployment and ongoing use. It also involves tracking changes to the requirement over the course of the project.
There are two main types of requirements traceability:
- Forward Traceability: This is used to ensure that the project progresses in the desired direction. It involves tracing the requirements from their origins through to the corresponding parts of the system design and implementation. It helps to ensure that all requirements have been addressed in the design and implementation phases.
- Backward (or Reverse) Traceability: This is used to trace the requirement back to its origin. It’s useful for ensuring the implemented system remains aligned with the stated requirements and project scope. It can also help to understand the impact on the system if a requirement changes.
Requirements traceability helps to:
- Verify that all requirements of the system are fulfilled by the implementation.
- Validate that the system only includes features requested in the requirements and avoids feature creep.
- Manage and control changes to the requirement.
- Maintain and verify compliance with standards and regulations.
Traceability is usually maintained through the use of a traceability matrix, also known as a Requirements Traceability Matrix (RTM), which is a table that links requirements to their origins and traces them throughout the project life cycle. Each requirement is given a unique identifier and is tracked across various stages of development and testing, ensuring that the final product meets the defined requirements and that all requirements have been tested.