The CMMI includes two representations, staged and continuous, due largely to the model's legacy. The CMMI model is founded on source models that employed either the staged representation (software engineering) or the continuous representation (systems engineering). Rather than risk alienating members from either engineering discipline, the authors of the CMMI decided to provide both representations.
Early adopters of the CMMI tend to favor the representation inherited from their legacy model. The CMMI's continuous representation has taken most software engineering groups out of their comfort zones. It's new to them, it's different from what they're used to, and therefore they perceive it as wrong/bad/evil. Besides, it has a level 0 and everybody knows that real models start at level 1!
Not too terribly long after completing the Intro to CMMI course, a process improvement consultant found herself in the midst of a battle between a Software Engineering Process Group (SEPG) and its process improvement sponsor. The SEPG was very much in favor of the continuous representation, because the members perceived it gave them more flexibility in implementing improvements as well as a more granular means of planning and tracking their progress. The sponsor, who wanted to use the tried-and-true staged representation, brought the consultant in for one day to arbitrate a peaceful resolution to this lingering conflict.
After spending a few hours with the SEPG to gain a better understanding of that perspective, the consultant met individually with the sponsor. They talked for an hour before lunch , and it was pretty obvious that the sponsor was adamant about using the staged representation. Based on the consultant's experience (as well as her personal comfort) with the CMM for Software, she tended to agree with the sponsor. Now all she had to do was figure out how to ease the SEPG into the "correct" way of thinking.
Over lunch, the sponsor was bragging about his daughter , gloating that she had achieved a 3.8 grade point average in her freshman year at an Ivy League school. "It's funny ," the consultant mused, "using a 'staged GPA representation' she would only be a 3." His jaw tightened as he pondered the remark. "It's worse than that," the sponsor finally admitted, "to date she has received nine A's and one C, so she'd only be a 2." The remainder of the lunchtime conversation focused on how to implement the continuous representation throughout the sponsor's organization!
What Is Software Quality?
Software Development Process Models
Fundamentals of Measurement Theory
Software Quality Metrics Overview
Applying the Seven Basic Quality Tools in Software Development
Defect Removal Effectiveness
The Rayleigh Model
Exponential Distribution and Reliability Growth Models
Quality Management Models
In-Process Metrics for Software Testing
Complexity Metrics and Models
Metrics and Lessons Learned for Object-Oriented Projects
Measuring and Analyzing Customer Satisfaction
Conducting In-Process Quality Assessments
Conducting Software Project Assessments
Dos and Donts of Software Process Improvement
Using Function Point Metrics to Measure Software Process Improvements
A Project Assessment Questionnaire