This chapter is from the book
This chapter is from the book
This chapter is from the book
Choosing a Representation
If you are new to process improvement and are not familiar with either the staged or continuous representation, you cannot go wrong if you choose one representation or the other. There are many valid reasons to select either representation.
If you have been using a CMM and you are familiar with a particular representation, we suggest that you continue to use that representation because it will make the transition to CMMI easier. Once you have become completely comfortable with CMMI, you might then decide to use the other representation.
Because each representation has advantages over the other, some organizations use both representations to address particular needs at various times in their improvement programs. We provide the advantages and disadvantages of each representation to help you decide which representation is best for your organization.
TABLE 1.1 Comparative Advantages of Continuous and Staged Representations
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Continuous Representation |
Staged Representation |
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Grants explicit freedom to select the order of improvement that best meets the organiza ion's business objectives and mitigates the organization's areas of risk |
Enables organizations to have a predefined and proved improvement path |
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Enables increased visibility of the capability achieved in each individual process area |
Focuses on a set of processes that provide an organization with a specific capability that is characterized by each maturity level |
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Provides a capability-level rating that is used primarily for improvement in an organization and is rarely communicated externally |
Provides a maturity-level rating that is often used in internal management communication, statements external to the organization, and during acquisitions as a means to qualify bidders |
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Allows improvements of different processes to be performed at different rates |
Summarizes process-improvement results in a simple form—a single maturity-level number |
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Reflects a newer approach that does not yet have the data to demonstrate its ties to return on investment |
Builds on a relatively long history of use that includes case studies and data that demon strate proved return on investment |
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Provides an easy migration from the SECM to the CMMI |
Provides an easy migration from the Software CMM to CMMI |
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Affords an easy comparison of process improvement to ISO/IEC 15504 because the organization of process areas is derived from 15504- |
Allows comparison to 15504, but the organization of process areas does not correspond to the organization used in ISO/IEC 15504 |
The continuous representation offers a flexible approach to process improvement. An organization may choose to improve the performance of a single process-related trouble spot, or it can work on several areas that are closely aligned to the organization's business objectives. The continuous representation also allows an organization to improve different processes at different rates. There are some limitations on an organization's choices because of the dependencies among some process areas.
Capability levels are used to measure the improvement path through each process area from an unperformed process to an optimizing process. For example, an organization may wish to strive for reaching capability level 2 in one process area and capability level 4 in another. As the organization's process reaches a capability level, it sets its sights on the next capability level for that same process area or decides to widen its scope and create the same level of capability across a larger number of process areas.
If you know the processes that need improvement in your organization and you understand the dependencies among the process areas described in CMMI, the continuous representation would be a good choice for your organization.
Staged Representation
The staged representation offers a systematic, structured way to approach process improvement one step at a time. Achieving each stage ensures that an adequate improvement has been laid as a foundation for the next stage.
Process areas are organized by maturity levels that take much of the guesswork out of process improvement. The staged representation prescribes the order for implementing each process area according to maturity levels, which define the improvement path for an organization from the initial level to the optimizing level. Achieving each maturity level ensures that an adequate improvement foundation has been laid for the next maturity level and allows for lasting, incremental improvement.
If you do not know where to start and which processes to choose to improve, the staged representation is a good choice for you. It gives you a specific set of processes to improve that have been determined through more than a decade of research and experience in the software community.
Comparison of the Continuous and Staged Representations
Table 1.1 compares the advantages of each representation and may assist you with determining which representation is right for your organization.
Factors in Your Decision
Three categories of factors that may influence your decision when selecting a representation are business, culture, and legacy.
Business Factors
An organization with mature knowledge of its own business objectives is likely to have a strong mapping of its processes to its business objectives. Such an organization may find the continuous representation useful to appraise its processes and in determining how well the organization's processes support and meet its business objectives.
If an organization with a product lines focus decides to improve processes across the entire organization, it might be served best by the staged representation. The staged representation will help an organization select the critical processes to focus on for improvement.
The same organization may opt to improve processes by product line. In that case, it might select the continuous representation—and a different appraised rating of capability might be achieved for each product line. Both approaches are valid. The most important consideration is which business objectives you would like your process improvement program to support and how these business objectives align with the two representations.
Cultural Factors
Cultural factors to consider when selecting a representation have to do with an organization's ability to deploy a process improvement program. For instance, an organization might select the continuous representation if the corporate culture is process based and experienced in process improvement or has a specific process that needs to be improved quickly. An organization that has little experience in process improvement may choose the staged representation, which provides additional guidance on the order in which changes should occur.
Legacy
If an organization has experience with a staged representation, it may be wise to continue with the staged representation of CMMI, especially if it has invested resources and deployed processes across the organization that are associated with a staged representation. The same is true for the continuous representation.
Both staged and continuous representations were included in CMMI so that the communities that have used them successfully could continue in a manner that is comfortable and familiar as well as successful.
Why Not Both Representations?
Whether used for process improvement or appraisals, both representations are designed to offer essentially equivalent results. More than eighty percent of the CMMI model's content is common to both representations. Therefore, an organization need not select one representation over another.
In fact, an organization may find utility in both representations. It is rare that an organization will implement either representation exactly as prescribed. Organizations that are successful in process improvement often define an improvement plan that focuses on the unique needs of that organization and therefore use the principles of both the staged and continuous representations.
For example, organizations that select the staged representation and are at maturity level 1 often implement the maturity level 2 process areas but also the Organizational Process Focus process area, which is included at maturity level 3. Another example is an organization that chooses the continuous representation for guiding its internal process improvement effort and then chooses the staged representation to conduct an appraisal.