An Overview of Capability Maturity Models and CMMI
What is a Capability Maturity Model?
The Software Engineering Institute or SEI defines capability maturity models as models that contains the essential effective processes for a discipline and evolutionary path from ad hoc and immature to maturity. Different types of businesses and business functions follow different Capability Maturity Models. The CMMI framework contains the rules and methods for generating Capability Maturity Models.
A CMMI model component is one part of the CMMI model, such as specific business practices CMMI requires. One example of a CMMI model component is Configuration Management or Drawing Control. Other CMMI model components are specific goals based on the type of business and business function. For example, CMMI may set specific quality levels for a manufacturer like Six Sigma, but requires a specific rate of change for an engineering group and budget variance limits in the finance department.
What is CMMI?
Capability Maturity Model Integration or CMMI is a methodology to improve business processes over time.
CMMI's models contain best practices, recommended business processes that SEI and Carnegie Mellon have researched and found to be the best way to perform those business activities.
CMM and CMMI are registered trademarks to the Software Engineering Institute (SEI) and Carnegie Mellon University.
Process Improvement and CMMI
Capability Maturity Model or CMM uses a scale from 1 to 5, rating the maturity of a business' processes.
CMMI level 1 means that business processes are being performed.
CMMI level 2 means that business processes are managed and supervised as they are performed.
CMMI level 3 requires that business processes be formally defined. The business has policies and procedures that describe how work should be done and what work products each process should create.
CMM level 4 is described as "quantitatively managed". CMMI level 4 requires that company use quantitative measures to manage their processes and performance.
CMM level 5 requires proof that a company has successfully implemented continuous process improvement initiatives while meeting all of the business process requirements of level 4. CMMI allows you to use Six Sigma, Lean Six Sigma or Total Quality Management methods to reach level 5. CMMI level 5 is called the optimizing level. Level 5 is the highest Capability Maturity Model score a company can receive.
Businesses that do not perform basic processes or have no documentation on what they do and how they do it can be said to have an incomplete process and given a capability level of 0. However, zero is not a formally recognized CMMI rating.
Capability Maturity Model Terminology
CMMI constellations are sets of CMMI components that apply to a particular area like finance, engineering or quality. CMMI uses the term Body of Knowledge or BOK to refer to the information that employees within a particular job function are expected to know. SCAMPI stands for Standard CMMI Appraisal Method for Process Improvement. This is the formal appraisal of a business to determine its CMMI rating.
A CMMI achievement profile lists all process areas and their capability levels. For example, the engineering department's configuration management procedures may meet CMMI level 4 while the contracts group only meets CMMI level 3. Capability evaluations measure the performance of suppliers against a contract and the business processes of the supplier. The CMMI product suite includes the CMMI framework, CMMI model and the appraisal method to be used for the CMMI model.
Expected CMMI components are actions that need to be taken or processes to be implemented to reach compliance with a mandatory CMMI component. If the mandatory action called for in the CMMI model isn't possible, equivalent alternative practices must be used. CMMI uses the term product life cycle to describe the process of envisioning a product, designing it, building it, supporting it and then disposing of it.
Product Data Management systems can hold Product Lifecycle Management or PLM data. CMMI mandates quality management systems for all work products, from service delivery to manufacturing. Quality control requires measuring products to determine whether or not they meet specific criteria like size, weight or functional criteria.
Quality assurance is the set of business processes to ensure that product quality is properly assessed, documented and managed. Quality control may require that a company measures the dimensions of a part interface. Quality assurance involves the periodic calibration of inspection machines and training of employees in statistical process control.
Root Cause Analysis
What Does Capability Maturity Model Integration Require?
CMMI starts with documenting current business practices, procedures and policies. You must know what you do and how you do it. Then companies must collect metrics on how consistently these procedures are applied and the results of these processes. How do you review drawings now? What is the change rate, the number of change requests submitted per document each year? How long does it take to create a baseline change request or purchase order, and what steps do you follow?
CMMI requires businesses to practice configuration management with their product designs, perform product verification and software verification and have disaster recovery and business continuity plans. CMMI recommends that businesses engage in risk management during project planning. CMMI advises companies to practice supplier management, rating the quality of products suppliers receive along with their ability to deliver on schedule. CMMI states that businesses must practice requirements management, where the requirements for deliverables like software must be formally defined, agreed upon and rated in priority before any work like coding can begin. CMMI lists specific practices it recommends, but alternative practices are replacement processes used in an effort to meet the CMMI model.
CMMI requires the generation and tracking of corrective action reports, the actions taken to remedy a problem or correct a deviation from approved business procedures. CMMI’s higher levels require companies have formal reviews of their business processes to ensure that they meet CMMI’s models even as the business’ processes change. CMMI aims to create a business with only stable processes, where all special causes of variation are removed.
CMMI outlines recommended best practices on how to run all areas of your business and measure performance of these business processes.
CMMI references other major industry standards. CMM suggests that companies meet ISO 9000 quality standards. CMMI calls out ISO 12207, ISO 15504 and ISO 15288. CMMI also refers to ANSI / EIA standard 632.
What Is CMMI Certification and How Do You Get CMMI Certified?
CMMI certification may be a requirement of government or major corporate contracts. In order to use CMMI products, a company must enter a license agreement with SEI. CMMI certifications are only awarded after appraisals are performed by SCAMPI Lead Appraisers.
CMMI certifications can be achieved by whole companies, work sites or departments. A software development group could meet CMMI level 5 while the engineering group only meets level 4. One business division could be level 3 while another work site is at level 4.