The Immaturity of CMM
This article was originally published in the September =9194 issue of
by James Bach
(Formerly of Borland International)
The Software Engineering Institute's (SEI) Capability Maturity Model
(CMM) gets a lot of publicity. Given that the institute is funded by the
US Department of Defense to the tune of tens of millions of dollars each
year , this should come as no surprise=97 the folks at the SEI are the
official process mavens of the military, and have the resources to spread
the word about what they do. But, given also that the CMM is a broad, and
increasingly deep, set of assertions as to what constitutes good software
development practice, it's reasonable to ask where those assertions come
from, and whether they are in fact complete and correct.
My thesis, in this essay, is that the CMM is a particular mythology of
software process evolution that cannot legitimately claim to be a natural
or essential representation of software processes.
The CMM is at best a consensus among a particular group of software
engineering theorists and practitioners concerning a collection of
effective practices grouped according to a simple model of organizational
evolution. As such, it is potentially valuable for those companies that
completely lack software savvy, or for those who have a lot of it and
thus can avoid its pitfalls.
At worst, the CMM is a whitewash that obscures the true dynamics of
software engineering, suppresses alternative models. If an organization
follows it for its own sake, rather than simply as a requirement mandated
by a particular government contract, it may very well lead to the
collapse of that company's competitive potential. For these reasons, the
CMM is unpopular among many of the highly competitive and innovative
companies producing commercial shrink-wrap software.
A short description of the CMM
The CMM  was conceived by Watts Humphrey, who based it on the
earlier work of Phil Crosby. Active development of the model by the SEI
began in 1986.
It consists of a group of "key practices", neither new nor
unique to CMM, which are divided into five levels representing the stages
that organizations should go through on the way to becoming
"mature". The SEI has defined a rigorous process assessment
method to appraise how well a organization satisfies the goals associated
with each level. The assessment is supposed to be led by an authorized
The maturity levels are:
1. Initial (chaotic, ad hoc, heroic)
2. Repeatable (project management, process discipline)
3. Defined (institutionalized)
4. Managed (quantified)
5. Optimizing (process improvement)
One way companies are supposed to use the model is first to assess their
maturity level and then form a specific plan to get to the next level.
Skipping levels is not allowed.
The CMM was originally meant as a tool to evaluate the ability of
government contractors to perform a contracted software project. It may
be suited for that purpose; I don't know. My concern is that it is also
touted as a general model for software process improvement. In
that application, the CMM has serious weaknesses.
Shrink-wrap companies, which have also been called commercial
off-the-shelf firms or software package firms, include Borland, Claris,
Apple, Symantec, Microsoft, and Lotus, among others. Many such companies
rarely if ever manage their requirements documents as formally as the CMM
describes. This is a requirement to
achieve level 2, and so all of these companies would probably fall into
level 1 of the model.
Criticism of the CMM
A comprehensive survey of criticism of the CMM is outside the scope
of this article. However, Capers Jones and Gerald Weinberg are two
In his book Assessment & Control of Software Risks , Jones
discusses his own model, Software Productivity Research (SPR), which was
developed independently from CMM at around the same time and competes
with it today. Jones devotes a chapter to outlining the weaknesses of the
CMM. SPR accounts for many factors that the CMM currently ignores, such
as those contributing to the productivity of individual engineers.
In the two volumes of his Quality Software Management series
[12,13], Weinberg takes issue with the very concept of maturity as
applied to software processes, and instead suggests a paradigm based on
patterns of behavior. Weinberg models software processes as
interactions between humans, rather than between formal constructs. His
approach suggests an evolution of "problem-solving leadership"
rather than canned processes.
General problems with CMM
I don't have the space to expand fully on all the problems I see in
the CMM. Here are the biggest ones from my point of view as a process
specialist in the shrink-wrap world:
=B7 The CMM
has no formal theoretical basis. It's based on the experience of
"very knowledgeable people". Hence, the de facto underlying
theory seems to be that experts know what they're doing. According to
such a principle, any other model based on experiences of other
knowledgeable people has equal veracity.
=B7 The CMM
has only vague empirical support. That is, the empirical support for CMM
could also be construed to support other models. The model is based
mainly on experience of large government contractors, and Watts
Humphrey's own experience in the mainframe world. It does not account for
the success of shrink-wrap companies, and levels 1, 4, and 5 are not well
represented in the data: the first because it is misrepresented, the
latter two because there are so few organizations at those levels. The
SEI's, Mark Paulk can cite numerous experience reports supporting CMM,
and he tells me that a formal validation study is underway. That's all
well and good, but the anecdotal reports I've seen and heard regarding
success using the CMM could be interpreted as evidence for the success of
people working together to achieve anything. In other words,
without a comparison of alternative process models under
controlled conditions, the empirical case can never be closed. On the
contrary, the case is kept wide open by ongoing counterexamples in the
form of successful level 1 organizations, and by the curious lack of data
regarding failures of the CMM (which may be due to natural reluctance on
the part of companies to dwell on their mistakes, or of the SEI to record
=B7 The CMM
reveres process, but ignores people. This is readily apparent to anyone
who is familiar with the work of Gerald Weinberg, for whom the problems
of human interaction define engineering. By contrast, both Humphrey and
CMM mention people in passing , but both also decry them as unreliable
and assume that defined processes can somehow render individual
excellence less important. The idea that process makes up for mediocrity
is a pillar of the CMM, wherein humans are apparently subordinated to
defined processes. But, where is the justification for this? To render
excellence less important the problem solving tasks would somehow have to
be embodied in the process itself. I've never seen such a process, but if
one exists, it would have to be quite complex. Imagine a process
definition for playing a repeatably good chess game. Such a process
exists, but is useful only to computers; a process useful to humans has
neither been documented nor taught as a series of unambiguous steps.
Aren't software problems at least as complex as chess problems?
=B7 The CMM
reveres institutionalization of process for its own sake. Since the CMM
is principally concerned with an organization's ability to commit, such a
bias is understandable. But, an organization's ability to commit is
merely an expression of a project team's ability to execute. Even if
necessary processes are not institutionalized formally, they may very
well be in place, informally, by virtue of the skill of the team members.
Institutionalization guarantees nothing, and efforts to institutionalize
often lead to a bifurcation between an oversimplified public process and
a rich private process that must be practiced undercover. Even if
institutionalization is useful, why not instead institutionalize a system
for identifying and keeping key contributors in the organization, and
leave processes up to them?
=B7 The CMM
contains very little information on process dynamics. This makes it
confusing to discuss the relationship between practices and levels with a
CMM proponent, because of all the hidden assumptions. For instance, why
isn't training on level 1 instead? Training is especially important at
level 1, where it may take the form of mentoring or of generic training
in any of the skills of software engineering. The answer seems to be that
nothing is placed at level 1, because level 1 is defined merely as
not being at level 2. The hidden assumption here is that who we are, what
problems we face, and what we're already doing doesn't matter: just
get to level 2. In other words, the CMM doesn't perceive or adapt to
the conditions of the client organization. Therefore training or any
other informal practice at level 1, no matter how effective it is, could
be squashed accidentally by a blind and static CMM. Another example: Why
is defect prevention a level 5 practice? We use project post mortems at
Borland to analyze and improve our processes -- isn't that a form of
defect prevention? There are many such examples I could cite, based on a
reading of the CMM 1.1 document (although I did not review the voluminous
Key Practices document) and the appendix of Humphrey's Managing the
Software Process . Basically, most and perhaps all of the key
practices could be performed usefully at level 1, depending on the
particular dynamics of the particular organization. Instead of actually
modeling those process dynamics, the way Weinberg does in his work, the
CMM merely stratifies them.
=B7 The CMM
encourages displacement of goals from the true mission of improving
process to the artificial mission of achieving a higher maturity level. I
call this "level envy", and it generally has the effect of
blinding an organization to the most effective use of its resources. The
SEI itself recognizes this as a problem and has taken some steps to
correct it. The problem is built in to the very structure of the model,
however, and will be very hard to exorcise.
Feet of clay: The CMM's fundamental misunderstanding of level 1
The world of technology thrives best when individuals are left
alone to be different, creative, and disobedient. -- Don Valentine,
Silicon Valley Venture Capitalist 
Apart from the concerns mentioned above, the most powerful argument
against the CMM as an effective prescription for software processes is
the many successful companies that, according the CMM, should not exist.
This point is most easily made against the backdrop of the Silicon
Tom Peters's, Thriving on Chaos , amounts to a manifesto for
Silicon Valley. It places innovation, non-linearity, ongoing revolution
at the center of its world view. Here in the Valley, innovation reigns
supreme, and it is from the vantage point of the innovator that the CMM
seems most lost. Personal experience at Apple and Borland, and contact
with many others in the decade I've spent here, support this view.
Proponents of the CMM commonly mistake its critics as being anti-process,
and some of us are. But a lot of us, including me, are process
specialists. We believe in the kinds of processes that support
innovation. Our emphasis is on systematic problem-solving leadership to
enable innovation, rather than mere process control to enable
Innovation per se does not appear in the CMM at all, and it is only
suggested by level 5. This is shocking, in that the most innovative firms
in the software industry, (e.g., General Magic, a pioneer in personal
digital communication technology) operate at level 1, according to the
model. This includes Microsoft, too, and certainly Borland . Yet, in
terms of the CMM, these companies are considered no different than any
failed startup or paralyzed steel company. By contrast, companies like
IBM, which by all accounts has made a real mess of the Federal Aviation
Administration's Advanced Automation Project, score high in terms of
maturity (according to a member of a government audit team with whom I
Now, the SEI argues that innovation is outside of its scope, and that the
CMM merely establishes a framework within which innovation may more
freely occur. According to the literature of innovation, however, nothing
could be further from the truth. Preoccupied with predictability, the CMM
is profoundly ignorant of the dynamics of innovation.
Such dynamics are documented in Thriving on Chaos,
Reengineering the Corporation , and The Fifth Discipline
, three well known books on business innovation. Where innovators
advise companies to get flexible, the CMM advises them to get
predictable. Where the innovators suggest pushing authority down in the
organization, the CMM pushes it upward. Where the innovators recommend
constant constructive innovation, the CMM mistakes it for chaos at level
1. Where the innovators depend on a trail of learning experiences, the
CMM depends on a trail of paper.
Nowhere is the schism between these opposing world-views more apparent
than on the matter of heroism. The SEI regards heroism as an
unsustainable sacrifice on the part of particular individuals who have
special gifts. It considers heroism the sole reason that level 1
companies succeed, when they succeed at all.
The heroism more commonly practiced in successful level 1 companies is
something much less mystical. Our heroism means taking initiative to
solve ambiguous problems. This does not mean burning people up and
tossing them out, as the SEI claims. Heroism is a definable and teachable
set of behaviors that enhance and honor creativity (as a unit of United
Technologies Microelectronics Center has shown ). It is communication,
and mutual respect. It means the selective deployment of processes, not
according to management mandate, but according to the skills of the
Personal mastery is at the center of heroism, yet it too has no place in
the CMM, except through the institution of a formal training program.
Peter Senge , has this to say about mastery:
"There are obvious reasons why companies resist encouraging
personal mastery. It is 'soft', based in part on unquantifiable concepts
such as intuition and personal vision. No one will ever be able to
measure to three decimal places how much personal mastery contributes to
productivity and the bottom line. In a materialistic culture such as
ours, it is difficult even to discuss some of the premises of personal
mastery. 'Why do people even need to talk about this stuff?' someone may
ask. 'Isn't it obvious? Don't we already know it?'"
This is, I believe, the heart of the problem, and the reason why CMM
is dangerous to any company founded upon innovation. Because the CMM is
distrustful of personal contributions, ignorant of the conditions needed
to nurture non-linear ideas, and content to bury them beneath a
constraining superstructure, achieving level 2 on the CMM scale may very
well stamp out the only flame that lit the company to begin with.
I don't doubt that such companies become more predictable, in the way
that life becomes predictable if we resolve never to leave our beds. I do
doubt that such companies can succeed for long in a dynamic world if they
work in their pajamas.
An alternative to CMM
If not the maturity model, then by what framework can we guide
genuine process improvement?
Alternative frameworks can be found in generic form in Thriving on
Chaos, which contains 45 "prescriptions", or The Fifth
Discipline, which presents--not surprisingly--five disciplines. The
prescriptions of Thriving on Chaos are embodied in an
organizational tool called The Excellence Audit, and The Fifth
Discipline Fieldbook , which provides additional guidance in
creating learning organizations, is now available.
An advantage of these models is that they provide direction, without
mandating a particular shape to the organization. They actually provide
guidance in creating organizational change.
Specific to software engineering, I'm working on a process model at
Borland that consists of a seven-dimensional framework for analyzing
problems and identifying necessary processes. These dimensions are:
business factors, market factors, project deliverables, four primary
processes (commitment, planning, implementation, convergence), teams,
project infrastructure, and milestones. The framework connects to a set
of scaleable "process cycles". The process cycles are
repeatable step by step recipes for performing certain common tasks.
The framework is essentially a situational repository of heuristics for
conducting successful projects. It is meant to be a quick reference to
aid experienced practitioners in deciding the best course of action.
The key to this model is that the process cycles are subordinated to the
heuristic framework. The whole thing is an aid to judgment, not a
prescription for institutional formalisms. The structure of the
framework, as a set of two-dimensional grids, assists in process
tailoring and asking "what if...?"
In terms of this model, maturity means recognizing problems (through the
analysis of experience and use of metrics) and solving them (through
selective definition and deployment of formal and informal processes),
and that means developing judgment and cooperation within teams. Unlike
the CMM, there is no a priori declaration either of the problems, or the
solutions. That determination remains firmly in the hands of the
The disadvantage of this alternative model is that it's more complex, and
therefore less marketable. There are no easy answers, and our progress
cannot be plotted on the fingers of one hand. But we must resist the
temptation to turn away from the unmeasurable and sometimes ineffable
reality of software innovation.
After all, that would be immature.
In the five years since I wrote this article, neither the CMM
situation, nor my assessment of it, has changed much. The defense
industry continues to support the CMM. Some commercial IT organizations
follow it, many others don't. Software companies pursuing the great
technological goldrush of our time, the Internet, are ignoring it in
droves. Studies alleging that the CMM is valuable don't consider
alternatives, and leave out critical data that would allow a full
analysis of what's going on in companies that claim to have moved up in
CMM levels and to have benefited for that reason.
One thing about my opinion has shifted. I've become more comfortable with
the distinction between the CMM philosophy, and the CMM issue list. As a
list of issues worth addressing in the course of software process
improvement, the CMM is useful and benign. I would argue that it's
incomplete and confusing in places, but that's no big deal. The problem
begins when the CMM is adopted as a philosophy for good software
Still, it has become a lot clearer to me why the CMM philosophy is so
much more popular than it deserves to be. It gives hope, and an illusion
of control, to management. Faced with the depressing reality that
software development success is contingent upon so many subtle and
dynamic factors and judgments, the CMM provides a step by step plan to do
something unsubtle and create something solid. The sad part
is that this step-by-step plan usually becomes a substitute for genuine
education in engineering management, and genuine process
Over the last few years, I've been through Jerry Weinberg's classes on
management and change artistry: Problem Solving Leadership, and
the Change Shop. I've become a part of his Software Engineering
Management Development Group program, and the SHAPE forum.
Information about all of these are available at
In my view, Jerry's work continues to offer an excellent alternative to
the whole paradigm of the CMM: managers must first learn to see, hear,
and think about human systems before they can hope to control them.
Software projects are human systems=97deal with it.
One last plug. Add to your reading list The Logic of Failure, by
Dietrich Dorner. Dorner analyzes how people cope with managing complex
systems. Without mentioning software development or capability maturity,
it's as eloquent an argument against CMM philosophy as you'll find.
1. Berti, Pat, "Four Pennsylvania schools await defense
cuts.", Pittsburgh Business Times, Jan 22, 1990 v9 n24
2. Coplien, James, "Borland Software Craftsmanship: a New Look at
Process, Quality and Productivity", Proceedings of the 5th Borland
International Conference, 1994
3. Couger, J. Daniel; McIntyre, Scott C.; Higgins, Lexis F.; Snow, Terry
A., "Using a bottom-up approach to creativity improvement in IS
development.", Journal of Systems Management, Sept 1991 v42 n9
4. Hammer, Michael; Champy, James, Reengineering the Corporation,
5. Humphrey, Watts, Managing the Software Process, ch. 2, Addison-Wesley,
6. Jones, Capers, Assessment & Control of Software Risks,
7. Paulk, Mark, et al, Capability Maturity Model 1.1
8. Peters, Tom, The Tom Peters Seminar: Crazy Times Call for Crazy
Organizations, Random House, 1994
9. Peters, Tom, Thriving on Chaos: Handbook for a Management Revolution,
10. Senge, Peter, The Fifth Discipline, Doubleday, 1990
11. Senge, Peter, The Fifth Discipline Fieldbook, Doubleday, 1994
12. Weinberg, Gerald M., Quality Software Management, v. 1 Systems
Thinking, Dorset House, 1991
13. Weinberg, Gerald M., Quality Software Management, v. 2 First-order
measurement, Dorset House, 1993