The Scenario-based Engineering Process (SEP) is a user-centered system development process that combines features of business process re-engineering with software engineering. It was developed by professionals from multiple disciplines - computer science and engineering, cognitive science, information systems, and psychology - working with users and shareholders in complex domains.

The result is a manageable user-centered, prototyping-intensive development process that is applicable in situations such as: dynamic, changing environments; human-intensive problems; long-term solutions; large, complex problem or solution space; and the need for partial replication of the system to more than one site.