The traceability matrix: what it is and what is it used for

The traceability matrix, also called Requirements Traceability Matrix or RTM, provides documentation of the links between the proposed requirements, concerning the project output, and the test phase.

Simply put, it is a document to map and track requirements and to ensure that an adequate level of testing is achieved for each of these requirements.

Indeed, when developing a product or service, you want to make sure that this output matches what was requested. To ensure this, the traceability matrix and tests are essential.

Traceability is the process of reviewing all defined test cases for any requirement.

Traceability allows one to determine which requirements generated the most defects during the testing process.

The traceability matrix is, essentially, a tool that helps to ensure that the purpose, requirements and results of the project remain in line with what was initially agreed.

Why is traceability of requirements necessary?

The requirements traceability matrix provides an accurate connection between requirements, test instances and defects.

Generally it ensures good output quality as all functionalities are tested.

Quality control can be achieved when the final product is tested for unexpected scenarios with minimal defects and all functional and non-functional requirements are met.

From that moment on, quality improvement can also be achieved.

Benefits of using requirements traceability matrix

The benefits of utilizing a traceability matrix are many, here are the most important ones:

• The final product is tested and includes all the required functionalities that meet users’ needs and expectations. The end customer must get what they want. There cannot be any negative surprises for the user, if this happens it would not be a nice experience for anyone.

• The final product developed and delivered to the customer must include only the required and expected features. The extra functionalities present in the product may initially look interesting until an overburden of time, budget and effort to develop them is experienced. Extra features can also become a source of defects and cause problems for a customer during or after use.

• The activity of the project manager and their team can be set out clearly because they work first on the implementation of the requirements, which are of the highest priority, according to the client’s needs. If the high priority requirements are given clearly, the output elements can be developed and implemented in this order of importance. In this way the entire project plan can be set up clearly.

• At the time of testing all the most important and top priority features can be examined, without losing time with unnecessary testing. This helps to produce a quality product that meets expectations.

 How to efficiently run tests with the help of a traceability matrix

To effectively run tests with the help of the traceability matrix, it is important to follow four basic rules:

Have a good communication channel

In case of modifications suggested by stakeholders or users, they must be promptly reported to the project team. Without this timely communication, accurate testing cannot be guaranteed.

Determine test scenarios priority

Identifying high priority test scenarios can be a challenging task. Trying to test all scenarios is in many cases an unachievable task, so the goal of the test must be very clear from the business and end-user point of view.

Process implementation

Testing process must be clearly defined taking into account factors such as technical infrastructure and implementations, team skills, past experience, organizational structures and processes undertaken, project estimates of costs, time and resources. A uniform implementation of the process considering the mentioned factors ensures that every person involved in the project is on the same page.

Effective implementation of the testing strategy

An effective testing strategy, supported by a traceability matrix, plays an important role in planning ahead for all types of critical challenges, which further helps to develop a better product.

How to create a requirements traceability matrix

In the process of creating a requirements traceability matrix, the following operations must be conducted:

• Set objectives: Only one question needs to be answered is: “What purpose will the traceability matrix serve?” Here is an example of an objective to explain the concept: To create a traceability matrix to keep track of test cases and bugs that will be affected if changes are made to the requirements.
• Collect artifacts: Once the objective is determined, it is necessary to know what artifacts you will need to achieve it. To create a traceability matrix of requirements, you will need to:
• Requirements
• Test cases
• Test results
• Bugs

The next step will be to collect these artifacts.

• Create a traceability matrix template: For a requirements tracking matrix template, an Excel spreadsheet can be used and a column can be added for each artifact collected.

• Artifacts addition: Now you can add requirements, test cases, test results and bugs in their respective columns depending on the results achieved.

• Update traceability matrix: The updating of the traceability matrix is an ongoing work that continues until the completion of the project. If the requirements change, it is mandatory to update the traceability matrix. If a new test case is added or a new bug is found, you need to update it in the traceability matrix of requirements.

Bottom line, the requirements traceability matrix is the way to map and track all customer and stakeholder requirements with test cases and defects detected.

It is a single document that has the main purpose of not losing track of test cases and therefore ensures that all the functionality of the final product is covered and tested.