6.3 Considerations for Staged and Continuous CMMI Representations
When considering the joint use of the staged representation of the CMMI with Six Sigma, the most frequently asked question relates to whether and how Six Sigma can be applied at lower maturity levels. The answer is that yes, Six Sigma can be applied at lower maturity. Two of the previously described sequencing scenarios call for Six Sigma to be used at lower maturity, and all of the strategies allow for this. The use of Six Sigma at lower maturity is different than at higher maturity and, in fact, contributes to an accelerated attainment of high maturity.
As depicted in Figure 6-3, Six Sigma philosophy, frameworks, and toolkits can all be leveraged at lower maturity. Even its measures can be used, although they may not reflect organizational performance (yet). If Six Sigma project portfolio management and methods are being employed, there is reasonable assurance that local improvements provide added value for the organization and are not just isolated exercises that will not contribute to the greater good. As such, there is a likelihood that these efforts will accelerate the CMMI solution—a key aspect of the value proposition for joint model implementation—because people will gain experience with the effective use of measurement and analysis to gain control of a situation and possibly optimize a process, albeit a local one. CMMI-compliant processes may be piloted and refined as part of individual project efforts. As an organization climbs the maturity ladder, the use of Six Sigma can continue, but now applied across organizational processes.
Figure 6-3 CMMI staged representation and Six Sigma
In the continuous representation, Six Sigma may be used to drive the design and/or improvement of any process area that has been selected for implementation, much as it may be used in the staged representation.
An additional usage of Six Sigma for the continuous representation relates to the selection and sequencing of process area implementation. An organization could use Six Sigma thinking to establish its highest-priority issues and the requisite process areas that need to be implemented to solve them [Vickroy 03]. It might also blend in a strategic prioritization of processes. For instance, an organization might choose to develop its capability in process areas that are tightly coupled with Six Sigma skills and methods—those that would enable it to effectively baseline and characterize process performance and issues, such as MA, QPM, and CAR. Figure 6-4 shows a possible scenario that could result when Six Sigma is used to prioritize issues and decide the order of implementation of the CMMI process areas. Alternatively, if new product introduction or market growth were a priority for the organization, it might choose to select the Engineering process areas as first priority. This is also indicated in Figure 6-4, by a dashed line.
Figure 6-4 CMMI continuous representation and Six Sigma: a possible scenario