Equivalent staging is a way to compare results
from using the continuous representation to those of the staged
representation. In essence, if you measured improvement relative to
selected process areas using capability levels in the continuous
representation, how would you compare that to maturity levels? Is this
Up to this point, we have not discussed process
appraisals in much detail. The SCAMPISM
method8 is used to
appraise organizations using CMMI, and one result of an appraisal is a
rating [SEI 2006b, Ahern 2005]. If the continuous representation is used
for an appraisal, the rating is called a “capability level profile.” If
the staged representation is used for an appraisal, the rating is called a
“maturity level rating” (e.g., maturity level
A capability level profile is a list of process
areas and the corresponding capability level achieved for each. This
profile enables an organization to track its capability level by process
area. The profile is called an “achievement profile” when it represents
the organization’s actual progress for each process area. Alternatively,
the profile is called a “target profile” when it represents the
organization’s planned process improvement objectives. Figure 3.3
illustrates a combined target and achievement profile. The gray portion of
each bar represents what has been achieved. The unshaded portion
represents what remains to be accomplished to meet the target
Figure 3.3: An Example of a Target and
An achievement profile, when compared with a
target profile, enables an organization to plan and track its progress for
each selected process area. Maintaining capability level profiles is
advisable when using the continuous representation.
Target staging is a sequence of target profiles
that describes the path of process improvement to be followed by the
organization. When building target profiles, the organization should pay
attention to the dependencies between generic practices and process areas.
If a generic practice depends on a process area, either to carry out the
generic practice or to provide a prerequisite product, the generic
practice may be much less effective when the process area is not
Although there are many reasons to use the
continuous representation, ratings consisting of capability level profiles
are limited in their ability to provide organizations with a way to
generally compare themselves with other organizations. Capability level
profiles could be used if each organization selected the same process
areas; however, maturity levels have been used to compare organizations
for years and already provide predefined sets of process areas.
Because of this situation, equivalent staging
was created. Equivalent staging enables an organization using the
continuous representation for an appraisal to convert a capability level
profile to the associated maturity level rating.
The most effective way to depict equivalent
staging is to provide a sequence of target profiles, each of which is
equivalent to a maturity level rating of the staged representation. The
result is a target staging that is equivalent to the maturity levels of
the staged representation.
Figure 3.4 shows a summary of the target
profiles that must be achieved when using the continuous representation to
be equivalent to maturity
levels 2 through 5. Each shaded area in
the capability level columns represents a target profile that is
equivalent to a maturity level.
Figure 3.4: Target Profiles and Equivalent
The following rules summarize equivalent
- To achieve maturity level 2, all
process areas assigned to maturity level 2 must achieve capability level
2 or higher.
- To achieve maturity level 3, all
process areas assigned to maturity levels 2 and 3 must achieve
capability level 3 or higher.
- To achieve maturity level
4, all process areas assigned to maturity levels 2, 3, and 4 must
achieve capability level 3 or higher.
- To achieve maturity level 5, all
process areas must achieve capability level 3 or higher.
These rules and the table for equivalent
staging are complete; however, you may ask why target profiles 4 and 5 do
not extend into the CL4 and CL5 columns. The reason is that maturity level
4 process areas describe a selection of the subprocesses to be stabilized
based, in part, on the quality and process-performance objectives of the
organization and projects. Not every process area will be addressed in the
selection and CMMI does not presume in advance which process areas might
be addressed in the selection.
So, the achievement of capability level 4 for
process areas cannot be predetermined because the choices depend on the
selections made by the organization in its implementation of the maturity
level 4 process areas. Thus, Figure 3.4 does not show target profile
4 extending into the CL4 column, although some process areas
will have achieved capability level 4. The situation for maturity level 5 and
target profile 5 is similar.
The existence of equivalent staging should not
discourage users of the continuous representation from establishing target
profiles that extend above capability level 3. Such a target profile would
be determined in part by the selections made by the organization to meet
its business objectives.