ABSTRACT
George Box [2], the statistician and scientist, is famous for stating repeatedly that “all models are wrong, but some are useful.” The quotation refers to statistically based models; however, the Software Engineering Institute (SEI) at Carnegie Mellon University (CMU) adopted it to characterize its approach to process improvement models. Successful process improvement is best achieved when the underpinnings for it are based on a model. But as stated by Box and pointed out by the SEI, there is no one model that is best suited for every organization in every industry. Different models tend to have a different focus. In most cases, they are developed for different business domains, although some overlap does exist. For example, project management practices are fairly consistent from model to model. Every model has strengths and elements that fit well in some environments, but not in others. An organization interested in process improvement must look at available models and determine which one fits best for the business needs.
66In this chapter we provide an overview of different process models, including:
The Capability Maturity Model Integration (CMMI), including:
– CMMI for Development (CMMI-DEV)
– CMMI for Acquisition (CMMI-ACQ)
– CMMI for Services (CMMI-SVC)
People Capability Maturity Model (P-CMM)
Personal and Team Software Process
Information Technology Infrastructure Library (ITIL)
Information Technology Service Standard (ISO 20000, which incorporates the service elements of ITIL)
CMU’s eSourcing Capability Models
ISO/IEC quality management Standard 9000
ISO software life cycle Standard 12207
ISO software processes assessment framework Standard 15504
ISO system engineering—system life-cycle processes Standard 15288.
This chapter provides a broad context regarding the various models’ suitability for an organization’s process improvement initiatives, and helps in tailoring the model that will be most useful for a specific organization. The purpose is not to compare and contrast the models or to make a recommendation as to which is best to use. It is only to describe what models are available and in what domains they are used. We will, however, emphasize the CMMI because it is a process improvement model in wide use throughout the world in software and systems development and maintenance. The SEI’s September 2008 report of appraisal results indicates that 3,553 Version 1.1 and Version 1.2 Class A SCAMPI appraisals based on Version 1.1 and Version 1.2 of the CMMI had been performed and reported in 2,168 participating companies in 63 countries through June 2008 [1]. Clearly, the data indicates widespread acceptance of the model for process improvement.
