A Technical History of the SEI

The Capability Maturity Model for Software
The Challenge: Consistent and Predictable Management of Software
Development.
In 1986, there was a general realization in the DoD and among defense contractors that certain
software engineering practices produced working software with increased consistency. However,
relatively few practitioners recognized these largely undocumented practices. Most companies
had established their own practices through experience, but the importance that software project
planning and tracking, commitment management, quality management, and configuration management
practices have in successfully managing software development—and the need for organizational
support to perform these practices effectively—was not broadly appreciated. Furthermore,
software tools supporting such activities were often developed by the organization and
displayed the idiosyncrasies particular to that organization. Frequently, the tool choice dictated
the defining and interaction of the processes. Nevertheless, examples of successful software development
programs did occur and the recognition that software could be managed by a defined
and measured process was reflected in an expanding body of literature by leading authors.
The DoD identified the management of the software component of programs as a major problem
area [DoD 1982], and the DoD STARS strategy envisioned a managed process well supported by
automated tools [Druffel 1983].
A Solution: The Capability Maturity Model for Software
In response to the DoD need, the SEI strategic plan identified the management of the software development
process—both by DoD program offices and defense contractors—as a fundamental focus
of the SEI [Barbacci 1985]. The SEI recruited a retiring executive from IBM who had been
instrumental in creating and managing IBM efforts toward greater software quality and predictability
and began work to define a process management framework in 1986. Shortly thereafter, the
Air Force program manager asked the SEI to conduct a study of “best practices.” The study became
key to the SEI’s efforts to define and implement its process management framework. Several
workshops were conducted with leading software professionals in the DoD, defense industry,
commercial industry, and academia to develop a consensus on the practices that consistently lead
to improved software development. To help organizations determine how well their work stacked
up against these practices, the SEI produced a Maturity Questionnaire [Humphrey 1988]. Response
to this questionnaire was overwhelmingly positive, both from the DoD and the defense industry.
Initially, the questionnaire identified a five-level model of organizational maturity based on the
implementation of software process management principles [Humphrey 1989]. After assisting
several organizations with their assessments and subsequent improvement efforts, the SEI produced
a guide for how organizations might manage that process [Fowler 1990]. As the community
began to adopt these ideas, they expressed a need for a more precise definition of the practices
and the underlying model.
CMU/SEI-2016-SR-027 | SOFTWARE ENGINEERING INSTITUTE | CARNEGIE MELLON UNIVERSITY 110
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