What Is a Requirements Traceability Matrix?

A requirements traceability matrix (RTM) is a document used in electronic product development to track requirements and their implementation. RTMs are large tables that record requirements and all the information associated with them, including design documents, schematics, and tests. 

They help engineers and designers to collaborate with project stakeholders and ensure that the project’s output aligns with its objectives. 

What Is Requirements Traceability?

Requirements traceability is the ability to track the relationships between project requirements, artifacts, and verification and validation testing throughout the product development process.

Requirements traceability can be forward, backward, or bidirectional.

• Forward traceability ensures that each requirement is linked to its corresponding design, implementation, and testing phases.
• Backward traceability allows teams to trace the final product back through the testing and design phases to the original requirements. It’s essential for validating that the delivered system aligns with the initial goals and objectives.
• Bidirectional traceability combines both forward and backward traceability, creating a comprehensive framework for managing requirements throughout the project lifecycle.

Requirements traceability helps electronics development teams:

• Ensure they are building the right product.
• Track requirements data, including testing to verify all requirements are met.
• Provide proof of requirement fulfillment for functional, safety, and regulatory compliance.

RTMs Trace Requirements from Conception to Testing

Imagine an electronics company is designing a new printed circuit board (PCB) for a medical device. Regulations require the PCB to be resistant to electromagnetic interference (EMI). 

• Requirement: The PCB must meet the EMI requirements outlined in standard IEC 60601-1-2.
• Traceability:
  • The design team needs to show how they will achieve this requirement in the PCB layout.
  • They might use specific design techniques, components, or shielding methods, all documented and linked to the requirement.
  • Testing procedures are designed and linked to this requirement.
  • Test results are documented and linked back to the original requirement.

A requirements traceability matrix ensures that the PCB's EMI resistance is not just a design goal, but a demonstrably achieved characteristic of the final product. 

Here’s a basic RTM record for the EMI resistance requirement.

How to Create a Requirements Traceability Matrix

You can create an RTM manually using a spreadsheet, or you can use dedicated requirements management software. RTM software provides automation and more reliable traceability, but manually tracing requirements may be a good option for simpler projects. 

Define Your Goals and Scope

What do you need the RTM document to track, and what kind of traceability are you aiming for (forward, backward, or bidirectional tracing)? Clearly defining your objectives upfront will help you determine the appropriate type of matrix and the information it should contain.

Decide on the Data You Need to Track

Once you've established your goals, you can determine which elements or artifacts to include in the matrix.

At a minimum, you'll need to include:

• Requirement ID: A unique identifier for each requirement.
• Requirement Description: A concise description of each requirement.
• Source: Where the requirement originated, whether it’s customer needs, business requirements, or regulatory standards.
• Related Artifacts: Documents, schematics, design elements, test cases, or other outputs related to the requirement.
• Verification Method: How the requirement will be tested.
• Verification Status: The status of the verification activities. For example: passed, failed, in progress, or not started.

Populate and Maintain the Matrix

Once you have your structure, you'll need to populate it with information gathered from sources like requirement documents and test plans. Remember, it’s a living document that should be updated as the project progresses and requirements evolve, new artifacts are created, and verification activities progress.

Maintaining the requirements traceability matrix is often the most work-intensive and error-prone part of requirements management. Requirements, artifacts, and tests must remain aligned. Complex projects with many requirements and frequent changes often fail to maintain traceability, resulting in expensive rework or even abandoned projects. 

Within Altium 365 Requirements & Systems Portal, managers can use the requirements module to enter and track the details from their requirements traceability matrix as a requirements list. The requirements list shown below lists parent and child requirements for each line item, as well as verification status.

The requirements list shows parent and child requirements for each line item, as well as verification status.

Requirements & Systems Portal goes one step further and helps automate many validation tasks that relate to objects in an Altium PCB layout. Objects from a PCB layout can be tagged directly in a line item, and these objects can be cross-probed into the PCB layout inside of Altium 365. Running a PCB design review from the requirements list allows this direct cross-probe into the PCB layout so that requirements can be quickly inspected and validated.

If you are starting from the schematics or the PCB, specific project requirements can be attached to objects in a schematic and the schematic sheet can be referenced within the project requirements. Overall, this speeds up reviews and helps ensure that requirements checking is not overlooked during project reviews.

Automating Traceability with Requirements Management Software

Altium 365 Requirements & Systems Portal automates traceability with an RTM designed for electronics product development. The portal reduces errors and rework while improving cross-team collaboration and communication.

• AI-assisted capture ensures your requirements are clear and consistent. 
• Requirements and changes are linked to entities in schematics. 
• Requirement changes automatically propagate throughout the project, ensuring stakeholders have up-to-date information.
• Version control provides a complete history of requirements evolution. 

Accelerate your requirements traceability workflows today.