Informative Material Is Important to CMMI Model Interpretation and Implementation
Purpose
The purpose of this update is to reaffirm and clarify the role that informative material in CMMI models has in process improvement and appraisals. In summary, the informative material supports correct interpretation and implementation of CMMI practices, but is neither required nor expected, nor is it to be used as part of a checklist in an appraisal. The informative material helps you to achieve a correct understanding of practices at all levels of a CMMI model.
Introduction
The April 2007 communication, CMMI Level 4-5 Interpretation and Implementations, emphasized the importance of the informative material at levels 4 and 5. It was written to address two related problems:
- There is variation in the interpretation of level 4 and 5 practices as evidenced in some of the SEI’s level 4 and 5 quality audits and lead appraiser certification activities.
- Level 4-5 supporting material in the Appraisal Disclosure Statement does not always reflect sufficient implementation of level 4-5 practices as described in the informative material.
That communication reaffirmed the importance of the informative material at levels 4 and 5 and described several actions the SEI is taking to assure the correct interpretation of level 4 and 5 practices. However, since that posting, the following additional concerns have been raised:
- Are the models and SCAMPI, V1.2: Method Definition Document (MDD) in conflict regarding the role of the informative material in implementing and appraising CMMI practices?
- Is the informative material at levels 2 and 3 somehow less important than the informative material at levels 4 and 5?
- Is informative material at levels 4 and 5 now required or expected material?
Response
Below, we respond to these concerns and further affirm the role of the informative material in correctly interpreting CMMI goals and practices.
1. Are the models and MDD in conflict regarding the role of the informative material in implementing and appraising CMMI practices?
There is no real conflict between the models and the MDD; they each emphasize both the importance and limitations of the informative material and what they say should be taken together. Below are five excerpts from either the CMMI-DEV model or SCAMPI MDD and an explanation of how these excerpts represent the same ideas concerning informative material:
- Informative components provide details that help organizations get started in thinking about how to approach the required and expected components. (CMMI-DEV, V1.2, page 16)
- A subpractice is a detailed description that provides guidance for interpreting and implementing a specific or generic practice. Subpractices may be worded as if prescriptive, but are actually an informative component meant only to provide ideas that may be useful for process improvement. (CMMI-DEV, V1.2, page 21)
- In making inferences about the extent to which practices are or are not implemented, appraisal teams draw on the entire model document to understand the intent of the model, and use it as the basis for their decisions. This comparison includes the required and expected model components (i.e., generic and specific goals, generic and specific practices) as well as informative material, such as model front matter, introductory text, glossary definitions, and subpractices. (MDD, page I-20)
- The use of informative material in the appraisal reference model to form a checklist is explicitly discouraged. (MDD, Page II-110)
- Direct artifact - The tangible outputs resulting directly from implementation of a specific or generic practice. An integral part of verifying practice implementation. May be explicitly stated or implied by the practice statement or associated informative material. (MDD, page III-50)
CMMI models make the distinction between what is expected (the practice statement) vs. guidance for interpreting and implementing a practice (subpractices). The MDD makes the distinction between the use of subpractices as a checklist vs. for making inferences about the extent to which practices are or are not implemented. The CMMI-DEV model and MDD each emphasize important nuances in the role of the informative material.
The key to deriving a correct understanding of the role of the informative material is to consider what both documents describe. Taken together, they describe informative material as neither expected nor to be used as part of a checklist in an appraisal. Taken together, they describe informative material as supporting a correct interpretation and implementation of the practices; and thus the informative material has a role in both implementing and appraising CMMI practices and goals.
CMMI models, including the informative material, are based on inputs (e.g., reviews, pilots, and implementation) of thousands of individuals and organizations over many years. Practice statements were written as concise distillations of these inputs while the informative material, also derived from these inputs, communicates important supporting context, explanations, and detail. Thus, to better understand a practice statement, it is necessary to consider the informative material. A careful reading of the informative material is essential to correctly understanding the required and expected material.
2. Is the informative material at levels 2 and 3 less important than the informative material at levels 4 and 5?
The original communication focused on problems occurring at levels 4 and 5—levels for which there exists relatively less real-world experience and information. However, the implementation of the practices at levels 4 and 5 relies on the solid foundation provided by an effective implementation of the practices at levels 2 and 3. However, level 2 and 3 practices are sometimes misinterpreted as well; therefore, the informative material at levels 2 and 3 is no less important. Finally, the quotes from CMMI-DEV, V1.2 and SCAMPI MDD given above do not make distinctions by level.
Therefore, to correctly interpret CMMI models, whether for process improvement or appraisal, it is important to understand all the informative material related to a particular practice. There is no distinction of relevance or emphasis on informative material by level.
3. Is informative material at levels 4 and 5 now required or expected material?
No. Informative material never was required or expected, and it still is not required or expected. However, this distinction is different than saying that informative material can be ignored. As already mentioned, CMMI practices are based on many thousands of inputs. Concise summaries of that input appear as goal or practice statements and important supportive detail appears as the informative material. Thus, to better understand a practice statement, it is necessary to consider the informative material.
Summary and Conclusion
In summary, the whole model must be studied and understood when using a CMMI model for process improvement and appraisal. There are no subsets of a CMMI model, e.g., the required and expected material, that can stand alone. The whole model must be understood and used to correctly interpret the practices.
All the informative material is important, regardless of level. It is not possible to understand a model practice statement by looking only at the practice statement—the informative material must be used.
With respect to evaluating the implementation of a practice, whether for process improvement or appraisal, CMMI users should consider all the informative material that explains a practice. The informative material helps to establish the intention of a practice, but does not specify how it must be implemented nor does it specify objective evidence requirements. Business goals, needs, and constraints drive selection of the implementation approach, methods, and techniques.
If you have questions or comments, send email to: cmmi-comments@sei.cmu.edu
