Understanding Capability Levels

To support those using the continuous representation, all CMMI models reflect capability levels in their design and content. A capability level consists of a generic goal and its related generic practices as they relate to a process area, which can improve the organization’s processes associated with that process area. As you satisfy the generic goal and its generic practices at each capability level, you reap the benefits of process improvement for that process area.
The six capability levels, designated by the numbers 0 through 5, are as follows:
0. Incomplete
1. Performed
2. Managed
3. Defined
4. Quantitatively Managed
5. Optimizing
The fact that capability levels 2 through 5 use the same terms as generic goals 2 through 5 is intentional because each of these generic goals and practices reflects the meaning of the capability levels in terms of goals and practices you can implement. (See the Generic Goals and Generic Practices section on page 75 for more information about generic goals and practices.) A short description of each capability level follows.


Capability Level 0: Incomplete
An “incomplete process” is a process that either is not performed or partially performed. One or more of the specific goals of the process area are not satisfied, and no generic goals exist for this level since there is no reason to institutionalize a partially performed process.

Capability Level 1: Performed
A capability level 1 process is characterized as a “performed process.” A performed process is a process that satisfies the specific goals of the process area. It supports and enables the work needed to produce work products.
Although capability level 1 results in important improvements, those improvements can be lost over time if they are not institutionalized. The application of institutionalization (the CMMI generic practices at capability levels 2 through 5) helps to ensure that improvements are maintained.


Capability Level 2: Managed
A capability level 2 process is characterized as a “managed process.” A managed process is a performed (capability level 1) process that has the basic infrastructure in place to support the process. It is planned and executed in accordance with policy; employs skilled people who have adequate resources to produce controlled outputs; involves relevant stakeholders; is monitored, controlled, and reviewed; and is evaluated for adherence to its process description. The process discipline reflected by capability level 2 helps to ensure that existing practices are retained during times of stress.


Capability Level 3: Defined
A capability level 3 process is characterized as a “defined process.” A defined process is a managed (capability level 2) process that is tailored from the organization’s set of standard processes according to the organization’s tailoring guidelines, and contributes work products, measures, and other process improvement information to the organizational process assets.
A critical distinction between capability levels 2 and 3 is the scope of standards, process descriptions, and procedures. At capability level 2, the standards, process descriptions, and procedures may be quite different in each specific instance of the process (e.g., on a particular project). At capability level 3, the standards, process descriptions, and procedures for a project are tailored from the organization’s set of standard processes to suit a particular project or organizational unit and therefore are more consistent, except for the differences allowed by the tailoring guidelines.Another critical distinction is that at capability level 3, processes are typically described more rigorously than at capability level 2. A defined process clearly states the purpose, inputs, entry criteria, activities, roles, measures, verification steps, outputs, and exit criteria. At capability level 3, processes are managed more proactively using an understanding of the interrelationships of the process activities and detailed measures of the process, its work products, and its services.


Capability Level 4: Quantitatively Managed
A capability level 4 process is characterized as a “quantitatively managed process.” A quantitatively managed process is a defined (capability level 3) process that is controlled using statistical and other quantitative techniques. Quantitative objectives for quality and process performance are established and used as criteria in managing the process. Quality and process performance is understood in statistical terms and is managed throughout the life of the process.


Capability Level 5: Optimizing
A capability level 5 process is characterized as an “optimizing process.” An optimizing process is a quantitatively managed (capability level 4) process that is improved based on an understanding of the common causes of variation inherent in the process. The focus of an optimizing process is on continually improving the range of process performance through both incremental and innovative improvements.

Advancing through Capability Levels
The capability levels of a process area are achieved through the application of generic practices or suitable alternatives to the processes associated with that process area.
Reaching capability level 1 for a process area is equivalent to saying that the processes associated with that process area are “performed processes.”
Reaching capability level 2 for a process area is equivalent to saying that there is a policy that indicates you will perform the process. There is a plan for performing it, resources are provided, responsibilities are assigned, training to perform it is provided, selected work products related to performing the process are controlled, and so on. In other words, a capability level 2 process can be planned and monitored just like any project or support activity.
Reaching capability level 3 for a process area assumes that an organizational standard process exists associated with that process area, which can be tailored to the needs of the project. The processes in the organization are now more consistently defined and applied because they are based on organizational standard processes.
Reaching capability level 4 for a process area assumes that this process area is a key business driver that the organization wants to manage using quantitative and statistical techniques. This analysis gives the organization more visibility into the performance of selected subprocesses that will make it more competitive in the marketplace.Reaching capability level 5 for a process area assumes that you have stabilized the selected subprocesses and that you want to reduce the common causes of variation within that process. Remember that variation is a natural occurrence in any process, so although it is conceptually feasible to improve all processes, it would not be economical to improve all processes to level 5. Again, you would concentrate on those processes that would help you to meet your business objectives.