Software Engineering Institute | Carnegie Mellon University
Software Engineering Institute | Carnegie Mellon University

Evolutionary Process for Integrating COTS-Based Systems

Does your legacy system provide significant business value?

Are you considering incrementally developing and deploying a modernized system?

Who Will Benefit?

  • Organizations that want to avoid the pitfalls of traditional processes in using commercial off-the-shelf (COTS) applications to meet business needs
  • Information Technology managers starting legacy system modernization efforts


EPIC is a management and engineering process for building, fielding, and supporting systems that leverage COTS products and other existing components.

COTS products offer the promise of rapid system delivery to end users, shared development costs with other customers, and opportunities for expanding business and mission capabilities. Yet, this promise is often not realized in practice. Many project teams try to use traditional, requirements-driven processes where they define requirements first, and form an architecture—only then do they search for COTS products. Practical experience shows that using COTS products requires new processes—as well as new skills, roles, and responsibilities.

EPIC does not simply evaluate and select the "right" COTS product. EPIC integrates COTS lessons learned and disciplined spiral engineering practice to define, build, field, and support COTS-based solutions that integrate one or more COTS products with legacy software, other pre-existing software components, and any required custom code. EPIC extends the Rational Unified Process® (RUP®) to provide a risk-based spiral framework to accommodate COTS products.

Throughout the life of the system, EPIC links the disparate stakeholders into a coherent team that simultaneously defines and manages tradeoffs among requirements and end-user business processes, system architecture and design, programmatics (i.e., cost and schedule and risk), and capabilities in the commercial marketplace. Throughout a project, EPIC drives from a strategic vision to an implemented and sustained solution by:

  • continuously leveraging marketplace forces
  • synchronizing system development with any necessary business process changes
  • facilitating interaction among stakeholders
  • evaluating products and negotiating needs based on hands-on experiments     ("try before you buy")
  • providing early mitigation of high- priority risks and visibility at key decision points


EPIC codifies these practices in a structured flow of key activities and artifacts. The detailed report provides

  • guides to the goal, objectives, exit criteria, activities, and artifacts for every phase of a project
  • guidelines and artifacts that provide pragmatic considerations to guide a number of COTS-unique activities


Currently, governmental and commercial organizations are piloting the process. The SEI seeks additional organizations for piloting.

To  facilitate a project's transition, an EPIC workshop is recommended. Mentoring services in the application of EPIC are also available.

Related Technical Reports

For More Information

Contact: Lisa  Brownsword
Software Engineering Institute
Carnegie Mellon University
4301 Wilson Blvd, Suite 902 Arlington, VA 22203