Process (systems engineering)

:"See also Process (disambiguation)."

CPRET Systems engineering

"'CPRET - A Process Definition according to AFIS (Association Française d'Ingénierie Système) dedicated to SE and open to all domains."'----

Introduction

The System Engineering normative documents and thoserelated to the Maturity Models are based on processes:for example, System Engineering processes of the EIA-632 and processes involved in a CMMI institutionalizationand improvement approach.

Process has numerous domain-dependent definitions. One of them, applied for the engineering activities is "a set ofinterdependent tasks transforming input elements intoproducts" (according to the EIA-632, for example).But, in practice, constraints imposed on the tasks andresources required to implement them are essential forexecuting the tasks mentioned and then, are involved intheir definition (example of the so-called technologicalconstraints).----

CPRET definition of a process

The complete definition of a process must include theConstraints, Products, Resources, input Elements andTransformations, leading to the CPRET acronym to beused as name and mnemonic of the selected definition.

CPRET representation of a process

The CPRET representation integrates theprocess Mission and Environment in order to offer anexternal standpoint.

CPRET definition modelling

Several models may correspond to a single definitiondepending on the language used (UML or anotherlanguage).

Note: process definition and modelling are interdependent notions but different the one from the other.----

CPRET terminology

The following components and terms apply to the CPRETdefinition of processes.

; Process

* A process is a set of transformations of input elements into products: respecting constraints,
* requiring resources,
* meeting a defined mission, corresponding to a specific purpose adapted to a given environment.

; Environment

Natural conditions and external factors impacting aprocess.

; Mission

Purpose of the process tailored to a given environment.

; Constraints

Imposed conditions, rules or regulations.

; Products

All what is generated by transformations. The productscan be of the desired or not desired type (e.g., thesoftware system and bugs, the refined products andwaste).

; Resources

Human resources, energy, time and other means requiredto carry out the transformations.

; Elements as inputs

Elements submitted to transformations for producing theproducts.

; Transformations

Operations organized according to a logic aimed atoptimizing the attainment of specific products from theinput elements, with the allocated resources and oncompliance with the imposed constraints.

CPRET through examples

The purpose of the following examples is to illustrate thedefinitions with concrete cases. These examples comefrom the Engineering field but also from other fields toshow that the CPRET definition of processes is not limitedto the System Engineering context.

; Examples of processes

* An engineering (EIA-632, ISO 15288, etc.)
* A concert
* A polling campaign
* A certification

; Examples of environment

* Various levels of maturity, technicality, equipment
* An audience
* A political system
* Practices

; Examples of mission

* Supply better quality products
* Satisfy the public, critics
* Have candidates elected
* Obtain the desired approval

; Examples of constraints

* Imposed technologies
* Correct acoustics
* Speaking times
* A reference model (ISO, CMMI, etc.)

; Examples of products

* A mobile telephone network
* A show
* Vote results
* A quality label

; Examples of resources

* Development teams
* An orchestra and its instruments
* An organization
* An assessment team

; Examples of elements as inputs

* Specifications
* Scores
* Candidates
* A company and its practices

; Examples of transformations

* Define an architecture
* Play the scores
* Make people vote for a candidate
* Audit the organization

CPRET Conclusions

Sharing a formalized definition of processes, whateverthe definition, means speaking the same language. The CPRET formalized definition systematically addresses the input Elements, Transformations and Products but also the other essential components of a Process, namely the Constraints and Resources. Among the resources, note the specificity of theResource-Time component which passes inexorably and irreversibly, with problems of synchronization and sequencing.

This definition states that environment is an external factor which cannot be avoided: as a matter of fact, a process is always interdependent with other phenomena including other processes.

References