Material for this article has been modified from The Enterprise Unified Process: Extending the Rational Unified Process by Scott W. Ambler, John Nalbone, and Michael Vizdos (Prentice Hall PTR, 2005).
The Rational Unified Process (RUP) has been adopted by thousands of organizations worldwide to help improve their software development processes. Although software development clearly is important, it’s only part of your overall information technology (IT) picture. Not only do you need to develop systems, you must operate and support them once in production. Furthermore, you must handle cross-system enterprise issues such as portfolio management, enterprise architecture, and strategic reuse, to name a few. The Enterprise Unified Process (EUP) extends the RUP to meet the real-world needs of mid- to large-sized organizations.
Many IT departments struggle to fulfill their primary mission—to deliver, operate, and support systems that enable the organization to meet its business goals. Business stakeholders want new systems that meet their actual needs delivered on time and on budget, they want to pay for functionality once and then reuse it again whenever appropriate, and they want their systems to work together effectively. Business stakeholders also want their systems to be properly operated and supported—they can’t afford to have systems become unavailable, nor can they afford to not receive help when it’s required.
It’s crucial for an IT organization to follow one or more software processes, and many organizations have chosen to adopt IBM’s Rational Unified Process, [1, 2] the lifecycle for which is depicted in Figure 1. The RUP development process helps to guide project teams in a consistent, affordable, and (relatively) predictable approach, which results in high-quality systems that meet the needs of stakeholders.
Figure 1 The RUP system lifecycle. 
The RUP is structured in two dimensions:
- Phases represent the four major stages that a development project goes through over time.
- Disciplines represent the logical activities that take place throughout the project.
The underlying assumption of this article is that your organization has adopted the RUP and is relatively successful with it. However, you’re now ready to take the next step, which is to extend the RUP to address all of your IT process needs.
Beyond Software Development
There is more to the lifecycle of a system than software development. The operation and support of a system after it’s in production are crucial to your success; why bother building the system if you can’t run it? The retirement of a system that is no longer needed or that is to be replaced by another system is also important. Production and retirement efforts require different skill sets and activities than those of system development; therefore, you need to go beyond the RUP. Figure 2 depicts a complete system lifecycle.
Figure 2 The complete system lifecycle. 
It doesn’t end here—most organizations deal with more than one system at a time, so they need a full IT process that reflects this reality. Cross-system enterprise issues such as portfolio management, enterprise architecture, enterprise administration, and strategic reuse are critical to your IT success. The challenge with enterprise activities is that it’s possible (and unfortunately common) for project momentum to grind to a halt when inefficient or unrealistic enterprise processes are thrust upon individual project teams. Enterprise groups must recognize that they exist not only to protect the enterprise but also to actively enhance system development efforts. They must support development teams, not hinder them.
You need to extend the RUP with the EUP, first introduced in 1999,  but enhanced over the years to its current incarnation, the lifecycle for which is depicted in Figure 3. The EUP extends the RUP lifecycle of Figure 1 to address both the complete system lifecycle and enterprise issues. In short, the RUP is a great start, on which the EUP builds.
Figure 3 The EUP v2004 IT lifecycle.