Software Testing - Traceability Matrix (RTM – Requirements Traceability Matrix)

A Traceability Matrix is a structured document used in software testing to map and track requirements throughout the software development and testing lifecycle. It establishes a clear relationship between requirements and corresponding test cases, ensuring that every requirement is properly implemented and tested.

Purpose of a Traceability Matrix

The primary objective of a Traceability Matrix is to ensure complete test coverage. It helps verify that:

• All functional and non-functional requirements are covered by test cases

• No extra or unnecessary test cases exist

• Every requirement can be traced through design, development, and testing

This makes it a critical artifact for quality assurance and audit compliance.

Types of Traceability Matrix

1. Forward Traceability

   • Maps requirements → test cases

   • Ensures every requirement is tested

2. Backward (Reverse) Traceability

   • Maps test cases → requirements

   • Ensures no extra test cases are written

3. Bidirectional Traceability

   • Combines both forward and backward tracing

   • Most commonly used in real projects

Typical Structure of a Traceability Matrix

Advantages of Traceability Matrix

• Ensures 100% requirement coverage

• Helps identify missing or redundant test cases

• Assists in impact analysis when requirements change

• Improves project transparency and control

• Useful during audits and reviews

When is RTM Prepared?

• Created after requirement analysis

• Updated throughout test design, execution, and defect tracking

• Maintained until project closure

Example 

If a project has 10 requirements, a Traceability Matrix confirms:

• All 10 requirements have corresponding test cases

• Each test case maps back to a valid requirement

• No requirement is left untested