Reusing Previous Assessment Results


Appraisal Classes

As mentioned, there are three classes of CMMI Appraisal Methods . Each class is distinguished by the degree of rigor associated with the application of the method. Class A is the most rigorous. Class B is slightly less rigorous; and Class C is the least rigorous . Exhibit 1 gives some idea of the expected differences between the methods in each class. The paragraphs that follow describe some of the details.

Exhibit 1: Appraisal Class Characteristics
start example

Characteristics

Class A

Class B

Class C

Amount of objective evidence gathered (relative)

High

Medium

Low

Rating generated

Yes

No

No

Resource needs (relative)

High

Medium

Low

Team size (relative)

Large

Medium

Small

Data sources (instruments, interviews, and documents)

Requires all three data sources

Requires only two data sources (one must be interviews)

Requires only one data source

Appraisal team leader requirement

Authorized Lead Appraiser

Authorized Lead Appraiser or person trained and experienced

Person trained and experienced

Source: Adapted from Appraisal Requirements for CMMI, Version 1.1, December 2001, Table 1: Characteristics of CMMI Appraisal Method Classes.

end example
 

Class A Appraisal Methods must satisfy all ARC requirements. A Class A Appraisal Method is the only method that can provide a rating. It requires three sources of data: instruments, interviews, and documents. An instrument is a survey or questionnaire provided to the organization, project, or individuals to complete prior to the on-site visit. It helps the organization define and document the scope of the appraisal, and gives the appraisal team members a "quick look" into the organization's structure and culture. An interview is a formal meeting between one or more members of the organization and the appraisal team or mini-team. During this interview, the interviewee represents the organization in some capacity, based on the role he performs . For example, the SCAMPI team may interview a project manager, a quality assurance representative, and the director of systems engineering. Many interviews are held with many members of the organizational unit. A document is just that ” a written work product or artifact that is used as evidence that a process is being followed. It can be a plan, meeting minutes, or a process description. The document can be either hard-copy or electronic.

A Class A Appraisal Method can additionally be either EIA 15504 conformant or non-EIA 15504 conformant. EIA 15504 is an international standard covering software process assessments. When an EIA 15504 comformant appraisal method is desired, there are additional requirements introduced to document how well processes perform. These include process profiles and product quality characteristics. Process profiles summarize the performance of processes found in the reviewed projects. Quality characteristics summarize the quality of the products and services provided, (e.g., defect density, reliability). Measuring and reporting process performance and quality characteristics is a fundamentally different approach to appraisal from previous CMM- related approaches.

A Class B Appraisal Method has fewer requirements than a Class A method. Class B requires only two sources of data (interviews and either instruments or documents). Data sufficiency and the draft presentation are optional with Class B. Data sufficiency means that for all specific and generic practices reviewed, validated observations exist. These observations are adequate to understand the extent of implementation of the practice, are representative of the organizational unit, and are representative of the life-cycle phases in use within the organizational unit. Draft presentation of findings (strengths and weaknesses based on valid observations) is used to get feedback for the people interviewed by formally presenting the draft findings before finalizing the findings. Data sufficiency and draft presentation are optional in Class B in order to reduce the amount of time needed for the appraisal. The result of an appraisal without data sufficiency and a draft presentation is an appraisal done in a shorter amount of time and effort, but with possibly less confidence in the findings.

A Class C Appraisal Method has even fewer requirements than a Class B method. Class C requires only one source of data (interviews, instruments, or documents). Team consensus, observation validation, observation corroboration, data sufficiency, and draft presentation are optional. Team consensus refers to a technique of team decision making regarding observations and findings that result in decisions that all team members are willing to support. Making observation validation and observation corroboration optional means that the team does not need to agree that enough data has been gathered for an observation and that observations need not be consistent with other observations. The result of an appraisal without team consensus, observation validation, observation corroboration, data sufficiency, and draft presentations is an appraisal done in a shorter amount of time and effort, but again, with much less confidence in the findings.

As of February 2003, only one "officially recognized" method is defined for any of these classes, and that is the SCAMPI, which satisfies the ARC requirements for a Class A Appraisal Method. Class B and Class C methods are left as an exercise for the reader by the SEI ” in other words, no approved methods currently exist. Many groups and organizations have created their own methods. A few words of caution: most groups and organizations have not really defined their methods in detail. They have just put the label of Class B and Class C on approaches that they previously employed to assess themselves and their clients .

Which Appraisal Method Class Should I Use?

Organizations involved in process improvement often use a range of methods to assess their improvement progress. Many organizations undergo process improvement using the CMMI in order to be rated at a particular level. Therefore, these organizations will need a Class A Appraisal Method at some time, and today that means a SCAMPI. The use of a Class B or Class C appraisal will depend largely on the organization's process improvement and appraisal strategy. Examples follow.

  • Strategy One. A Class B appraisal is used to initiate an organizational-level process improvement program by identifying the majority of weaknesses against the CMMI. The process improvement plan is based on the identified weaknesses. Class C appraisals would then be performed periodically to measure progress against the process improvement plan and to determine readiness for a follow-on Class B or Class A appraisal.

  • Strategy Two. Class C appraisals are used on subsets of the organization. These subsets are based on business areas or project size. The process improvement plan is based on the aggregation of the weaknesses found. Because the Class C appraisal is less detailed, the weaknesses are addressed across the organization, not just in the subset where found. A Class B appraisal would be performed after six months or a year of performing against the process improvement plan to determine readiness for a Class A appraisal.

  • Strategy Three. A Class A appraisal is used to initiate an organizational-level process improvement program. The process improvement plan is based on the identified weaknesses. A Class B appraisal would be performed after six months or a year of performing against the process improvement plan to determine readiness for a second Class A appraisal for an official rating.

In most situations, Strategy Three would be recommended because:

  • The most weaknesses are found in a Class A appraisal with the highest confidence level.

  • More organizational learning occurs through the formal appraisal process.

  • More organizational buy-in is possible, particularly for internal team members.




Interpreting the CMMI(c) A Process Improvement Approach
Interpreting the CMMI (R): A Process Improvement Approach, Second Edition
ISBN: 142006052X
EAN: 2147483647
Year: 2005
Pages: 205

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