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.

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 The SEI capability maturity model

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

21 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)

22 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)