Traceability is a powerful feature of RequisitePro that allows you to manage the effect of requirement change. You can link two requirements of the same type or of different types to indicate that they are related to or dependent on each other. The linkage takes the form of tracing a requirement to or from another requirement. In an Attribute Matrix, Traced-to and Traced-from columns are attributes used to describe requirements.
Here's how it works. Let's say you want to develop a Web-based retail outlet that notifies customers by e-mail when their purchases have been shipped. To satisfy this feature requirement, you develop a system in which e-mail notification is part of the procedure for shipping items to customers (a use-case requirement). You can then trace this use-case requirement to the feature requirement.
When you establish traceability between two requirements, any change to one requirement means that the traceability relationship must be re-examined to see whether it is still valid. RequisitePro gives you a visual cue telling you to do that.