For a successful study, design and development of the enterprise architecture, a thorough insight into the essence of the work and operation of an enterprise, is a crucial factor. As the well-known Zachman and other modern frameworks illustrate, enterprise processes and process modeling are one of the fundamental components of enterprise architecture for providing such an insight. Like building construction in which construction drawings or blueprints play crucial roles, enterprise process models are critical in developing enterprise architecture. Moreover, one may argue that the role of business process modeling in enterprise architecture is similar to the floor plan that defines the boundaries of a building to be constructed. Therefore, a suitable enterprise process modeling approach that could capture the essential operations and reflect the cross-enterprise (cross-departmental) processes is a needed component to complement enterprise architecture. In this chapter, authors study, discuss, and review the practical role of enterprise process modeling in enterprise architecture using a real life organization-based case study. Authors introduce a modeling methodology that captures essential activities not only within a process but also from the enterprise perspective where cross departmental or enterprise processes are represented.