This presentation describes a sustainable methodology for using MBSE to model business processes. This proven approach enables customer and process owner participation so that the enterprise can better understand and be more responsive to customer needs. It increases the value of business processes to customers by incorporating their needs into the SE model. Using an iterative interview based on the Six Sigma SIPOC model, the approach has been successfully demonstrated in several enterprise-wide programs. It has consistently yielded a solid, sustainable path to meeting the enterprise challenges. The SE model derived from the interviews produces a clear picture of the enterprise processes that deliver its business objectives. Incremental and agile, the approach is flexible and scalable in conformity with management priorities. Because it is scalable it can be engaged at the point(s) of greatest need and scaled out from there. Because it is agile it can provide real time help for critical needs even before achieving complete solutions. It is accountable at regular intervals allowing for measuring and monitoring progress in order to adjust and manage the speed and direction of the process. The approach shares many characteristics and principles with other “best practice” models for organizational improvement and maturation. There is solid convergence with improvement and design models such as CMMI, Lean Six Sigma and Agile and Iterative Development. It also facilitates the development of the Services Oriented Architecture (SOA) structure that provides efficient and effective delivery of service capabilities along an enterprise service bus to the process or orchestration layer. The organization using this approach can deliver system-derived functional requirements and capabilities that are grounded in a clear picture of the enterprise process needs. It provides a sound and complete SE model from which to continuously improve and mature the enterprise processes.