Requirements develop over the course of a project from coarse-grained epics to detailed user stories by a continuous process of defining and redefining. Requirements Engineering should ensure that during the whole development, the total set of requirements remains integer and consistent, thus preventing unnecessary refactoring, delays and cost overruns.
Today, we see a shift of focus from single-issue requirements elicitation for a single client to holistic solution provision for all stakeholders; organisations only define certain project scope, and requirements engineering creates solutions that remove a problem or facilitate a goal. Therefore, emphasis on the engineering part is growing, whereas the need for (documented) requirements in decreasing.
Basis factors like elicitation, specification and documentation are extended with success factors of solution design, elaboration and shared understanding.
This is summarised in the ‘RE Manifesto’.