Traceability Matrix

A method used to validate the compliance of a process or product with the requirements for that process or product.  The requirements are each listed in a row of the matrix and the columns of the matrix are used to identify how and where each requirement has been addressed.

A traceability matrix is a report from the requirements database or repository. What information the report contains depends on your need. Information requirements determine the associated information that you store with the requirements. Requirements management tools capture associated information or provide the capability to add it.

In a software development process, a traceability matrix is a table that correlates any two baselined documents that require a many to many relationship to determine the completeness of the relationship. It is often used with high-level requirements and detailed requirements of the software product to the matching parts of high-level design, detailed design, test plan, and test cases.

Common usage is to take the identifier for each of the items of one document and place them in the left column. The identifiers for the other document are placed across the top row. When an item in the left column is related to an item across the top, a mark is placed in the intersecting cell. The number of relationships are added up for each row and each column. This value indicates the mapping of the two items. Zero values indicate that no relationship exists. It must be determined if one must be made. Large values imply that the item is too complex and should be simplified.

To ease with the creation of traceability matrices, it is advisable to add the relationships to the source documents for both backward traceability and forward traceability. In other words, when an item is changed in one baselined document, it's easy to see what needs to be changed in the other.

Useful Traceability Matrices-

• Functional specification to requirements document: It shows that each requirement (obtained from a preliminary requirements statement provided by the customer or produced in the Concept Definition stage) has been covered in an appropriate section of the functional specification.
• Top level configuration item to functional specification: For example, a top level configuration item, Workstation, may be one of the configuration items that satisfies the function Input Order Information. On the matrix, each configuration item would be written down the left hand column and each function would be written across the top.

• Low level configuration item to top level configuration item: For example, the top level configuration item, Workstation, may contain the low level configuration items Monitor, CPU, keyboard, and network interface card.
• Design specification to functional specification verifies that each function has been covered in the design.
• System test plan to functional specification ensures you have identified a test case or test scenario for each process and each requirement in the functional specification.