Importance of Traceability Matrix in Testing

A Traceability Matrix is a document that maps or rather traces the relationship between two baseline documents. Here, one of the documents has the requirement specifications, whereas the other one has test cases. The Traceability Matrix is an essential document used during the software development lifecycle of a product, and it ensures completeness and transparency of the underlying product. It is also called Cross Reference Matrix (CRM) or  Requirement Traceability Matrix (RTM).

The below image shows a simple example of a Requirement Traceability Matrix for a high-level understanding.

This guide details the advantages of using a Traceability Matrix, its roles, types, and how you can create it.

Role of Traceability Matrix in Testing

Traceability Matrix tracks the association between test cases and requirements. Besides that, it plays many important roles over the entire testing cycle. Some of them are listed below.

• It ensures that your end product meets the customer’s requirements completely.
•  It helps trace the root cause of any bug logged in the process.
• It provides a glance over the testing progress roadmap and, as a result, enables the stakeholders to know the acceptable issues before the software goes to production.
• By showing the test coverage also helps the relevant stakeholders quickly determine the level of risk associated with getting the software pushed to production.

Advantages of Traceability Matrix

A Requirement Traceability Matrix can be greatly beneficial. Some of them are listed below.

• It ensures that all the requirements have been captured through the test cases
• It helps in assuring the client that the product is developed as per their requirements.
• It simplifies the process of identifying any loopholes or missing feature implementation.
• It ensures complete test coverage; as a result, all individual modules and their possible combinations have been tested.
• It can keep track of the overall test execution progress and bugs logged.
• It helps the team to keep track of the inclusion of all of the team members in each cycle of the SDLC.

Types of Software Testing Traceability Matrix

The traceability matrix can be divided into three different categories that are as follows:

1. Forward traceability
2. Backward or reverse traceability
3. Bi-directional traceability

• Forward traceability: In the case of Forward Traceability, as the name suggests, the requirements are mapped toward the forward direction of the test cases. It is used to ensure that all the client requirements are executed correctly and tested vigorously. The main objective of using a Forward Traceability Matrix is to verify whether the product development is heading in the right direction.

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• Backward or Reverse Traceability: In the case of Backward or Reverse Traceability, the requirements are mapped into the backward direction of test cases. The main objective of this is to ensure that the product is not consuming more than what is required in any area of coding, testing, or design elements that are actually not a part of business requirements, and hence, this ultimately keeps the project in the right direction. 

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• Bi-directional traceability: Bi-directional Traceability is a combination of both Forward and Backward Traceability matrices. It ensures that all business requirements have been covered in the test cases. It also keeps a watch on whether there have been any enhancements in the requirements due to any recently introduced bugs in the application.

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Parameters to be Included in Traceability Matrix

A Requirement Traceability Matrix is usually created according to the business requirements and standards. However, there are some common parameters that are always included. Few of them are mentioned below.

• Requirement ID
• Type
• Description
• Testcase ID
• Test case design 
• Test execution status
• Risks if any
• Defects and status
• Unit tests
• Integration tests 
• System tests 
• User Acceptance Test (UAT) Status

How to create a Traceability Matrix

Here are some of the steps that one must adhere to while creating a traceability matrix.

Step 1: Set an end goal as per the Client’s Requirements

The first step here is to ensure that all the requirements have been accurately captured and a goal has been set according to that. To understand this better, let us take an example of an e-commerce application for a makeup brand.

The main objective here will be to provide a seamless user experience for their buyers. In order to achieve that, there are two major capabilities needed. 

1. Products should get listed and filtered based on different categories
2. The application should support payments through different gateways 

Here, the goals can be mentioned as shown below:

• BR_1 – Product Viewing and Filtering: It should allow users to view and select different products and even filter them out based on different categories
• BR_2 – Payment Options:  It should allow users to make payments through different channels, like Credit Cards, Debit Cards, UPI, Internet Banking, etc.

Step 2: Gather all the required information and supportive documents

The second step here is to gather all the required information and supportive documents that are needed to build the traceability matrix effectively. Once all the information is in place, we can develop all possible test cases around it and capture it in Test Case Document(TSD). For example, in this case, the test areas can be further broken down as 

• BR_1 Product Viewing and Filtering:
• FR_1: Search icon and find text box- This should give users an option to directly type in their product name and click on the search icon to see the matching products

• FR_2: Filters- This should give the user an option to filter products from the catalog based on their type.

• BR_2 Payment Options:

• FR_3: By Credit Card- This should allow users to make payments by Credit Card.

• FR_4: By Debit Card – This should allow users to make payments by Credit Card.

• FR_5: By UPI- This should allow users to make payments through UPI.

• FR_6: By Internet Banking – This should allow users to make payments through Internet Banking, supporting all central banks.

Step 3: Put together all the information and prepare your Traceability Matrix.

Once all the necessary information has been captured, you can design the Traceability Matrix Template. The Matrix has no definite pattern and can be customized to the project requirements. 

Below is one sample Traceability Matrix template.

A. Test case for each requirement captured with their ID and Description

B. Requirements Traceability Matrix (RTM) template:

Step 4: Validate the end result through the matrix

Now that your matrix is ready, the next step is to take up all the mentioned test cases captured under TSD, update their status and bugs logged if any, and ensure all the relevant Functional Requirements captured under FSD are covered and as a result, ultimately Business Requirements are covered. Through this matrix, one can easily ensure all the necessary areas are tested thoroughly and, thus, ensure a seamless user experience.

The Requirements Traceability Matrix is an effective way to keep track of how the project is doing at each phase of the development lifecycle. It also assists relevant stakeholders in being sure that the requirements are meeting the expectations. If implemented correctly and accurately, RTM can easily help business leaders in avoiding end-moment issues and hassles and, as a result, improve the overall project quality, reliability, and efficiency.