Domain engineering
Encyclopedia
Domain engineering, also called product line engineering, is the entire process of reusing domain knowledge
in the production of new software systems. It is a key concept in systematic software reuse
. A key idea in systematic software reuse is the application domain
, a software area that contains systems sharing commonalities. Most organizations work in only a few domains
. They repeatedly build similar systems within a given domain with variations to meet different customer needs. Rather than building each new system variant from scratch, significant savings may be achieved by reusing portions of previous systems in the domain to build new ones.
The process of identifying domains, bounding them, and discovering commonalities and variabilities among the systems in the domain is called domain analysis
. This information is captured in models that are used in the domain implementation phase to create artifacts such as reusable components, a domain-specific language, or application generators that can be used to build new systems in the domain.
and number of symbols, to be reduced by over 50%, and the total number of lines of code to be reduced by nearly 75%.
Domain engineering focuses on capturing knowledge gathered during the software engineering
process. By developing reusable artifacts, components can be reused in new software systems at low cost and high quality. Because this applies to all phases of the software development cycle
, domain engineering also focuses on the three primary phases: analysis, design, and implementation, paralleling application engineering. This produces not only a set of software implementation
components relevant to the domain, but also reusable and configurable requirements and designs.
. Through the use of feature model
s (initially conceived as part of the feature-oriented domain analysis
method), domain analysis aims to identify the common points in a domain and the varying points in the domain. Through the use of domain analysis, the development of configurable requirements and architectures, rather than static configurations which would be produced by a traditional application engineering approach, is possible.
Domain analysis is significantly different from requirements engineering
, and as such, traditional approaches to deriving requirements are ineffective for development of configurable requirements as would be present in a domain model. To effectively apply domain engineering, reuse must be considered in the earlier phases of the software development life cycle. Through the use of selection of features from developed feature models, consideration of reuse of technology is performed very early and can be adequately applied throughout the development process.
Domain analysis is derived primarily from artifacts produced past experience in the domain. Existing systems, their artifacts (such as design document
s, requirement documents
and user manuals), standards, and customers are all potential sources of domain analysis input. However, unlike requirements engineering, domain analysis does not solely consist of collection and formalization of information; a creative component exists as well. During the domain analysis process, engineers aim to extend knowledge of the domain beyond what is already known and to categorize the domain into similarities and differences to enhance reconfigurability.
Domain analysis primarily produces a domain model
, representing the common and varying properties of systems within the domain. The domain model assists with the creation of architectures and components in a configurable manner by acting as a foundation upon which to design these components. An effective domain model not only includes the varying and consistent features in a domain, but also defines the vocabulary used in the domain and defines concepts, ideas and phenomena, within the system. Feature models decompose concepts into their required and optional features to produce a fully formalized set of configurable requirements.
The objective of domain design is to satisfy as many domain requirements as possible while retaining the flexibility offered by the developed feature model. The architecture should be sufficiently flexible to satisfy all of the systems within the domain while rigid enough to provide a solid framework upon which to base the solution.
Domain knowledge
Domain knowledge is that valid knowledge used to refer to an area of human endeavour, an autonomous computer activity, or other specialized discipline.Specialists and experts use and develop their own domain knowledge...
in the production of new software systems. It is a key concept in systematic software reuse
Code reuse
Code reuse, also called software reuse, is the use of existing software, or software knowledge, to build new software.-Overview:Ad hoc code reuse has been practiced from the earliest days of programming. Programmers have always reused sections of code, templates, functions, and procedures...
. A key idea in systematic software reuse is the application domain
Application domain
In Microsoft's Common Language Runtime , an application domain is a mechanism used to isolate executed software applications from one another so that they do not affect each other...
, a software area that contains systems sharing commonalities. Most organizations work in only a few domains
Domain (software engineering)
A domain is a field of study that defines a set of common requirements, terminology, and functionality for any software program constructed to solve a problem in the area of computer programming, known as domain engineering....
. They repeatedly build similar systems within a given domain with variations to meet different customer needs. Rather than building each new system variant from scratch, significant savings may be achieved by reusing portions of previous systems in the domain to build new ones.
The process of identifying domains, bounding them, and discovering commonalities and variabilities among the systems in the domain is called domain analysis
Domain analysis
In software engineering, domain analysis, or product line analysis, is the process of analyzing related software systems in a domain to find their common and variable parts. It is a model of wider business context for the system. The term was coined in the early 1980s by James Neighbors. Domain...
. This information is captured in models that are used in the domain implementation phase to create artifacts such as reusable components, a domain-specific language, or application generators that can be used to build new systems in the domain.
Purpose
Domain engineering is designed to improve the quality of developed software products through reuse of software artifacts. Domain engineering shows that most developed software systems are not new systems but rather variants of other systems within the same field. As a result, through the use of domain engineering, businesses can maximize profits and reduce time-to-market by using the concepts and implementations from prior software systems and applying them to the target system. The reduction in cost is evident even during the implementation phase. One study showed that the use of domain-specific languages allowed code size, in both number of methodsMethod (computer science)
In object-oriented programming, a method is a subroutine associated with a class. Methods define the behavior to be exhibited by instances of the associated class at program run time...
and number of symbols, to be reduced by over 50%, and the total number of lines of code to be reduced by nearly 75%.
Domain engineering focuses on capturing knowledge gathered during the software engineering
Software engineering
Software Engineering is the application of a systematic, disciplined, quantifiable approach to the development, operation, and maintenance of software, and the study of these approaches; that is, the application of engineering to software...
process. By developing reusable artifacts, components can be reused in new software systems at low cost and high quality. Because this applies to all phases of the software development cycle
Software development process
A software development process, also known as a software development life cycle , is a structure imposed on the development of a software product. Similar terms include software life cycle and software process. It is often considered a subset of systems development life cycle...
, domain engineering also focuses on the three primary phases: analysis, design, and implementation, paralleling application engineering. This produces not only a set of software implementation
Source code
In computer science, source code is text written using the format and syntax of the programming language that it is being written in. Such a language is specially designed to facilitate the work of computer programmers, who specify the actions to be performed by a computer mostly by writing source...
components relevant to the domain, but also reusable and configurable requirements and designs.
Phases of domain engineering
Domain engineering, like application engineering, consists of three primary phases: analysis, design, and implementation. However, where software engineering focuses on a single system, domain engineering focuses on a family of systems. A good domain model serves as a reference to resolve ambiguities later in the process, a repository of knowledge about the domain characteristics and definition, and a specification to developers of products which are part of the domain.Domain analysis
Domain analysis is used to define the domain, collect information about the domain, and produce a domain modelDomain model
A domain model in problem solving and software engineering can be thought of as a conceptual model of a domain of interest which describes the various entities, their attributes, roles and relationships, plus the constraints that govern the integrity of the model elements comprising that problem...
. Through the use of feature model
Feature model
Feature model is a compact representation of all the products of the Software Product Line in terms of "features". Feature models are visually represented by means of feature diagrams. Feature models are widely used during the whole product line development process and are commonly used as input...
s (initially conceived as part of the feature-oriented domain analysis
Feature-oriented domain analysis
Feature oriented domain analysis is a domain analysis method which introduced feature modelling to domain engineering. FODA was developed in 1990 following several U.S. Government research projects...
method), domain analysis aims to identify the common points in a domain and the varying points in the domain. Through the use of domain analysis, the development of configurable requirements and architectures, rather than static configurations which would be produced by a traditional application engineering approach, is possible.
Domain analysis is significantly different from requirements engineering
Requirements engineering
Requirements engineering is a systems and software engineering process which covers all of the activities involved in discovering, documenting and maintaining a set of requirements for a computer-based system...
, and as such, traditional approaches to deriving requirements are ineffective for development of configurable requirements as would be present in a domain model. To effectively apply domain engineering, reuse must be considered in the earlier phases of the software development life cycle. Through the use of selection of features from developed feature models, consideration of reuse of technology is performed very early and can be adequately applied throughout the development process.
Domain analysis is derived primarily from artifacts produced past experience in the domain. Existing systems, their artifacts (such as design document
Design document
A software design document is a written description of a software product, that a software designer writes in order to give a software development team an overall guidance of the architecture of the software project. An SDD usually accompanies an architecture diagram with pointers to detailed...
s, requirement documents
Software Requirements Specification
-Organization of an SRS:A Software Requirements Specification – a requirements specification for a software system – is a complete description of the behavior of a system to be developed. It includes a set of use cases that describe all the interactions the users will have with the software. In...
and user manuals), standards, and customers are all potential sources of domain analysis input. However, unlike requirements engineering, domain analysis does not solely consist of collection and formalization of information; a creative component exists as well. During the domain analysis process, engineers aim to extend knowledge of the domain beyond what is already known and to categorize the domain into similarities and differences to enhance reconfigurability.
Domain analysis primarily produces a domain model
Domain model
A domain model in problem solving and software engineering can be thought of as a conceptual model of a domain of interest which describes the various entities, their attributes, roles and relationships, plus the constraints that govern the integrity of the model elements comprising that problem...
, representing the common and varying properties of systems within the domain. The domain model assists with the creation of architectures and components in a configurable manner by acting as a foundation upon which to design these components. An effective domain model not only includes the varying and consistent features in a domain, but also defines the vocabulary used in the domain and defines concepts, ideas and phenomena, within the system. Feature models decompose concepts into their required and optional features to produce a fully formalized set of configurable requirements.
Domain design
Domain design takes the domain model produced during the domain analysis phase and aims to produce a generic architecture to which all systems within the domain can conform. In the same way that application engineering uses the functional and non-functional requirements to produce a design, the domain design phase of domain engineering takes the configurable requirements developed during the domain analysis phase and produces a configurable, standardized solution for the family of systems. Domain design aims to produce architectural patterns which solve a problem common across the systems within the domain, despite differing requirement configurations. In addition to the development of patterns during domain design, engineers must also take care to identify the scope of the pattern and the level to which context is relevant to the pattern. Limitation of context is crucial: too much context results in the pattern not being applicable to many systems, and too little context results in the pattern being insufficiently powerful to be useful. A useful pattern must be both frequently recurring and of high quality.The objective of domain design is to satisfy as many domain requirements as possible while retaining the flexibility offered by the developed feature model. The architecture should be sufficiently flexible to satisfy all of the systems within the domain while rigid enough to provide a solid framework upon which to base the solution.