A software component is a modular unit of software that encapsulates specific functionality. The desired characteristics of a component are reusability and maintainability.
Value
Components allow software development to assemble software with reliable parts rather than writing code for every aspect; allowing for implementation to be more like factory assembly than custom building.
Attributes
Desirable attributes of a component include but are not limited to:
- Cohesive – encapsulates related functionality
- Robust
- Substitutable – can be replaced by another component with the same interface
- Tested
Third-party
Some components are built in-house by the same organization or team building the software system. Some are third-party, developed elsewhere and assembled into the software system.
Component-based software engineering
For large-scale systems, component-based development encourages a disciplined process to manage complexity.
Framework
Some components conform to a framework technology that allows them to be consumed in a well-known way. Examples include: CORBA, COM, Enterprise JavaBeans, and the .NET Framework.
Modeling
Component design is often modeled visually. In Unified Modeling Language (UML) 2.0 a component is shown as a rectangle, and an interface is shown as a lollipop to indicate a provided interface and as a socket to indicate consumption of an interface.
History
The idea of reusable software components was promoted by Douglas McIlroy in his presentation at the NATO Software Engineering Conference of 1968. (One goal of that conference was to resolve the so-called software crisis of the time.) In the 1970s, McIlroy put this idea into practice with the addition of the pipeline feature to the Unix operating system.
Brad Cox refined the concept of a software component in the 1980s. He attempted to create an infrastructure and market for reusable third-party components by inventing the Objective-C programming language.
IBM introduced System Object Model (SOM) in the early 1990s.
Microsoft introduced Component Object Model (COM) in the early 1990s. Microsoft built many domain-specific component technologies on COM, including Distributed Component Object Model (DCOM), Object Linking and Embedding (OLE), and ActiveX.
References
- Pandey, Pankaj (11 July 2023). "Tutorial notes: Software Components and Connectors". medium.com. Retrieved 14 May 2024.
- Yadav, Sunny (16 April 2024). "Types of Software Components — With Examples". LinkedIn. Retrieved 14 May 2024.
- Douglas C. Schmidt. "Why Software Reuse has Failed and How to Make It Work for You". Retrieved 14 May 2024.
- Crnkovic, I.; Sentilles, S.; Vulgarakis, A.; Chaudron, M. R. V. (2011). "A Classification Framework for Software Component Models". IEEE Transactions on Software Engineering. 37 (5): 593–615. doi:10.1109/TSE.2010.83. S2CID 15449138.
- Lau, Kung-Kiu; Wang, Zheng (2007). "Software Component Models". IEEE Transactions on Software Engineering. 33 (10): 709–724. doi:10.1109/TSE.2007.70726. ISSN 0098-5589.
- McIlroy, Malcolm Douglas (January 1969). "Mass produced software components" (PDF). Software Engineering: Report of a conference sponsored by the NATO Science Committee, Garmisch, Germany, 7-11 Oct. 1968. Scientific Affairs Division, NATO. p. 79.
- Rainer Niekamp. "Software Component Architecture" (PDF). Gestión de Congresos - CIMNE/Institute for Scientific Computing, TU Braunschweig. p. 4. Archived from the original (PDF) on 2012-03-28. Retrieved 2011-07-29.
The modern concept of a software component largely defined by Brad Cox of Stepstone, => Objective-C programming language
- Brad Cox (1991). Object Oriented Programming: An Evolutionary Approach. Addison Wesley. ISBN 0-201-54834-8.
- Raphael Gfeller (December 9, 2008). "Upgrading of component-based application". HSR - Hochschule für Technik Rapperswill. p. 4. Retrieved 2011-07-29.
1990, IBM invents their System Object Model. 1990, as a reaction, Microsoft released OLE 1.0 OLE custom controls (OCX)
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A software component is a modular unit of software that encapsulates specific functionality The desired characteristics of a component are reusability and maintainability ValueComponents allow software development to assemble software with reliable parts rather than writing code for every aspect allowing for implementation to be more like factory assembly than custom building AttributesDesirable attributes of a component include but are not limited to Cohesive encapsulates related functionalityReusableRobustSubstitutable can be replaced by another component with the same interfaceDocumentedTestedThird partySome components are built in house by the same organization or team building the software system Some are third party developed elsewhere and assembled into the software system Component based software engineeringFor large scale systems component based development encourages a disciplined process to manage complexity FrameworkSome components conform to a framework technology that allows them to be consumed in a well known way Examples include CORBA COM Enterprise JavaBeans and the NET Framework ModelingAn example of interdependent components modeling a reservation system in UML Component design is often modeled visually In Unified Modeling Language UML 2 0 a component is shown as a rectangle and an interface is shown as a lollipop to indicate a provided interface and as a socket to indicate consumption of an interface HistoryThe idea of reusable software components was promoted by Douglas McIlroy in his presentation at the NATO Software Engineering Conference of 1968 One goal of that conference was to resolve the so called software crisis of the time In the 1970s McIlroy put this idea into practice with the addition of the pipeline feature to the Unix operating system Brad Cox refined the concept of a software component in the 1980s He attempted to create an infrastructure and market for reusable third party components by inventing the Objective C programming language IBM introduced System Object Model SOM in the early 1990s Microsoft introduced Component Object Model COM in the early 1990s Microsoft built many domain specific component technologies on COM including Distributed Component Object Model DCOM Object Linking and Embedding OLE and ActiveX ReferencesPandey Pankaj 11 July 2023 Tutorial notes Software Components and Connectors medium com Retrieved 14 May 2024 Yadav Sunny 16 April 2024 Types of Software Components With Examples LinkedIn Retrieved 14 May 2024 Douglas C Schmidt Why Software Reuse has Failed and How to Make It Work for You Retrieved 14 May 2024 Crnkovic I Sentilles S Vulgarakis A Chaudron M R V 2011 A Classification Framework for Software Component Models IEEE Transactions on Software Engineering 37 5 593 615 doi 10 1109 TSE 2010 83 S2CID 15449138 Lau Kung Kiu Wang Zheng 2007 Software Component Models IEEE Transactions on Software Engineering 33 10 709 724 doi 10 1109 TSE 2007 70726 ISSN 0098 5589 McIlroy Malcolm Douglas January 1969 Mass produced software components PDF Software Engineering Report of a conference sponsored by the NATO Science Committee Garmisch Germany 7 11 Oct 1968 Scientific Affairs Division NATO p 79 Rainer Niekamp Software Component Architecture PDF Gestion de Congresos CIMNE Institute for Scientific Computing TU Braunschweig p 4 Archived from the original PDF on 2012 03 28 Retrieved 2011 07 29 The modern concept of a software component largely defined by Brad Cox of Stepstone gt Objective C programming language Brad Cox 1991 Object Oriented Programming An Evolutionary Approach Addison Wesley ISBN 0 201 54834 8 Raphael Gfeller December 9 2008 Upgrading of component based application HSR Hochschule fur Technik Rapperswill p 4 Retrieved 2011 07 29 1990 IBM invents their System Object Model 1990 as a reaction Microsoft released OLE 1 0 OLE custom controls OCX permanent dead link
