CMMI & PROCESS PATTERNS

CMMI & PROCESS PATTERNS Lecture - 04

Topics covered CMMI- - Continuous model - Staged model PROCESS PATTERNS- - Generic Process pattern elements

The Capability Maturity Model Integration • SEI has developed a process meta-model on a set of system & software engg. capabilities that should be present as organization reaches diff. levels of process capability and maturity. • “The quality of a product is largely determined by the quality of the process that is used to develop and maintain it.”

The CMMI framework • The CMMI framework is the current stage of work on process assessment and improvement that started at the Software Engineering Institute in the 1980s. • The SEI’s mission is to promote software technology transfer particularly to US defence contractors. • It has had a profound influence on process improvement • Capability Maturity Model introduced in the early 1990s. • Revised maturity framework (CMMI) introduced in 2001.

Process capability assessment • Intended as a means to assess the extent to which an organisation’s processes follow best practice. • My providing a means for assessment, it is possible to identify areas of weakness for process improvement. • There have been various process assessment and improvement models but the SEI work has been most influential.

The SEI capability maturity model • Initial • Essentially uncontrolled • Repeatable • Product management procedures defined and used • Defined • Process management procedures and strategies defined and used • Managed • Quality management strategies defined and used • Optimising • Process improvement strategies defined and used

Problems with the CMM • Practices associated with model levels • Companies could be using practices from different levels at the same time but if all practices from a lower level were not used, it was not possible to move beyond that level • Discrete rather than continuous • Did not recognise distinctions between the top and the bottom of levels • Practice-oriented • Concerned with how things were done (the practices) rather than the goals to be achieved.

The CMMI model • An integrated capability model that includes software and systems engineering capability assessment. • The model has two instantiations • Staged where the model is expressed in terms of capability levels; • Continuous where a capability rating is computed.

CMMI model components • Process areas • 24 process areas that are relevant to process capability and improvement are identified. These are organised into 4 groups. • Goals • Goals are descriptions of desirable organisational states. Each process area has associated goals. • Practices • Practices are ways of achieving a goal - however, they are advisory and other approaches to achieve the goal may be used.

CMMI process areas 1

CMMI process areas 2

CMMI goals

CMMI practices

CMMI assessment • Examines the processes used in an organisation and assesses their maturity in each process area. • Based on a 6-point scale: • Not performed; • Performed; • Managed; • Defined; • Quantitatively managed; • Optimizing.

Continuous CMMI meta model • It describes a process in 2 dimensions as shown in fig. capability level & process area

Continuous model .. • PROCESS AREAS : PP- project planning REQM- requirement management MA- measurement & analysis CM- configuration management PPQA- process & product quality assurance Each process area is formally assessed against specific goals & practices and rated according to following capability levels

Capability Levels • Level 0 - Incomplete Process area is not performed or does not achieve all goals of level 1 • Level 1 – Performed achieved all goals of level 1 Work tasks conducted or performed • Level 2 – Managed All level 1 criteria satisfied In addition tasks & work products are monitored, controlled, reviewed & evaluated

Capability Levels • Level 3 – Defined All level 2 criteria satisfied In addition process is tailored from organizational standards of process to organizational process assets • Level 4 – Quantitatively managed All level 3 criteria satisfied In addition process is improved & controlled using measurements & quantitative assessment • Level 5 – Optimized All capability 4 criteria have been achieved In addition process area is adapted & optimized to meet changing customers need

CMMI staged Model • The CMMI defines each process area in terms of specific goals & specific practices required to achieve those goals • Specific Goals – establish the characteristics that must exist if the activities implied by a process area are to be effective • Specific practices- refine goal into a set of process related activities

Process Patterns • Software process can be defined as a collection of patterns • Templates or methods for describing important characteristics of software processes • Software teams can combine software patterns to construct processes that best meet the needs of specific projects

Process Patterns.. • Process patterns define a set of activities, actions, work tasks, work products and/or related behaviors • A template is used to define a pattern • Typical examples: • Customer communication (a process activity) • Analysis (an action) • Requirements gathering (a process task) • Reviewing a work product (a process task) • Design model (a work product)

Generic Process pattern elements • Meaningful pattern name • Intent (objective of pattern) • Type • Task pattern (defines engineering action or work task) • Stage pattern (defines framework activity for the process) • Phase pattern (defines sequence or flow of framework activities that occur within process) • Initial context (describes conditions that must be present prior to using pattern) • Problem (describes the problem to be solved by process pattern) • Solution (describes how to implement pattern correctly) • Resulting context (describes conditions that result when pattern has been implemented successfully) • Related patterns (links to patterns directly related to this one) • Known uses/examples (instances in which pattern is applicable)

CMMI & PROCESS PATTERNS