What is a requirement traceability matrix?
What are the differences between different requirement types and what are the advantages/disadvantages of using these matrices?
RTM is very important in software engineering and it is main thing that developer, QA, architect must update accordingly. Basically it covers all the relationships of your project where you can trace if there was change in requirement or after long time you came and work on project but you don't remember anything related to project.
Commonly it consist following columns in sheet
Req Id [Unique Id], Use Case Id, Class Id, User Interface Id, Test Case Id
Finally you can trace your requirement...
Traceability Matrix is very important tool to check whether all requirements are covered or not.
Generally business applications have lots of business rules which we divide in Use cases or base lined documents and give them a unique id, later we map them in traceability matrix so that if any requirement is missed out can be figured out.
Advantages Well how can you deliver a project unless all requirements are covered, The Matrix not only covers Business rules but also it determines Quality and Completeness of your Application.
Types Of Requirements is a vast, you can refer to this link. I hope it will give you a detailed idea about the requirement stuff.
A few answers here points out that a Requirement Traceability Matrix is necessary for developing software. I would argue that that is not necessarily the case, and that other software processes that do not involve a requirement traceability matrix can be highly successful in delivering high quality software that meets the users' demands.
If you however work in a regulated environment, e.g. writing software for medical devices, it is a requirement to have one. Because if you don't, your software will not be approved by regulatory authorities (which would be the FDA in the case of software for medical devices).
Actually, a requirement traceability matrix is just a tool for tracking requirements to design and test cases. Which tool you are using for the job is not important. What is important is that you are able to trace requirements to software architecture and test cases. What this means is that you must at all times be able to easily look up which test cases exists to verify the functionality implemented to support a specific requirement, but also which requirement existed to dictate one specific test case.
The Requirement Traceability Matrix (RTM) is a way to map business requirements and user stories to the test cases included in a test plan. The RTM’s purpose is to help ensure test coverage of business requirements including the number of tests for individual use cases. Forward and backward requirement traceability matrixes also show current defect counts providing test metrics by the requirement. If you want to learn more about the benefits of it, using different tools you can check this link: Requirement Traceability Matrix