Asset Management, also known as Component Management is a means of keeping track and optimizing your components throughout their existence, from one software development project to the next.
A software component is a system element offering a predefined service and able to communicate with other components. Clemens Szyperski and David Messerschmitt give the following five criteria for what a software component shall be to fulfil the definition:
A simpler definition can be: A component is an object written to a specification. It does not matter what the specification is: COM, Java Beans, etc., as long as the object adheres to the specification. It is only by adhering to the specification that the object becomes a component and gains features like reusability and so forth.
Software components often take the form of objects or collections of objects (from object-oriented programming), in some binary or textual form, adhering to some interface description language (IDL) so that the component may exist autonomously from other components in a computer.
When a component is to be accessed or shared across execution contexts or network links, some form of serialization (also known as marshalling) is employed to turn the component or one of its interfaces into a bitstream.
The idea that software should be componentized, built from prefabricated components, was first published in Douglas McIlroy's address at the NATO conference on software engineering in Garmisch, Germany, 1968 titled Mass Produced Software Components. This conference set out to counter the so-called software crisis. His subsequent inclusion of pipes and filters into the Unix operating system was the first implementation of an infrastructure for this idea.
IBM lead the way with their System Object Model, SOM in the early 1990s. Some claim that Microsoft paved the way for actual deployment of component software with OLE and COM. Today, several successful software component models exist.
Differences from object-oriented programming
The idea in object-oriented programming (OOP) is that software should be written according to a mental model of the actual or imagined objects it represents. OOP and the related disciplines of object-oriented design and object-oriented analysis focus on modeling real-world interactions and attempting to create 'verbs' and 'nouns' which can be used in intuitive ways, ideally by end users as well as by programmers coding for those end users.
Software components, by contrast, makes no such assumptions, and instead states that software should be developed by gluing prefabricated components together much like in the field of electronics or mechanics. It accepts that the definitions of useful components, unlike objects, can be counter-intuitive. In general it discourages anthropomorphism and naming, and is far more pessimistic about the potential for end user programming.
Some argue that this distinction was made by earlier computer scientists, with Donald Knuth's theory of "literate programming" optimistically assuming there was convergence between intuitive and formal models, and Edsger Dijkstra's theory in the article The Cruelty of Really Teaching Computer Science, which stated that programming was simply, and only, a branch of mathematics.
It takes significant effort and awareness to write a software component that is effectively reusable.
A computer running several software components is called an application server. Using this combination of application servers and software components is usually called distributed computing. The usual real-world application of this is in financial applications or business software.