A matrix is a tool that can be used to record, organize, and track the requirements throughout the lifecycle of the project. A matrix can help the business analyst to identify the sources, dependencies, relationships, and attributes of the requirements, as well as to monitor their status, changes, and traceability. A matrix can also facilitate the communication, verification, and validation of the requirements with the stakeholders, and ensure their alignment with the business needs and objectives. A matrix can be updated and reviewed regularly to reflect the current state of the requirements and the solution, and to obtain the approval and acceptance from the stakeholders. A common example of a matrix is the Requirements Traceability Matrix (RTM), which is a tool that links the requirements to the project scope, objectives, deliverables, and test cases12. References: PMI Professional in Business Analysis (PMI-PBA)Examination Content Outline3, page 18; Business Analysis for Practitioners: A Practice Guide4, page 92.