A trader for COTS components

Web COTStrader

Summary

In the last decade Component-Based Software Engineering is generating tremendous interest due to the development of plug-and-play reusable software, which has led to the concept of  "commercial off-the-shelf" (COTS) components. Although currently more a goal to pursue a than a reality, this approach moves organizations from application development to application assembly. Constructing an application now involves the use of prefabricated pieces, perhaps developed at diferent times, by diferent people, and possibly with diferent uses in mind. The ultimate goal, once again, is to be able to reduce developing times, costs, and eforts, while improving the flexibility, reliability, and reusability of the final application due to the (re)use of software components already tested and validated. Of course, this approach is challenging some of the current SE methods and tools. For instance, the traditional top-down development method based on successive refinements of the system requirements until a suitable concrete implementation of the final application's components is reached is no longer valid as such. In CBSE the system designer also has to have into account the specification of predeveloped COTS components that live in software repositories, that must be even considered when building the initial system's requirements in order to incorporate them into all phases of the development process [2, 3].

In this context, our particular long-term goal is to study the development of applications from COTS components, right from the specification of the application's software architecture. This specification describes the specification of abstract components, that may difier from the concrete specification of the COTS components residing in a given repository. In the simplest case each required service is separately specified, and each component implements just one service. This simple case is the one considered by traditional approaches, and therefore the search and matching processes of components have been de ned on a one-to-one basis [1, 4, 5].

However, this is not the common case in most real applications: in general, COTS components are coarse-grained components that integrate several services and over several interfaces. Think for instance in an Internet navigator or a Word processor: apart from their core services they also o er many diferent ones, like web page composition, spell checking, etc.  In addition, we also take into account the services that components require from other components, not only the supported ones.

References
 

1. J. Goguen, D. Nguyen, J. Meseguer, Luqi, D. Zhang, and V. Berzins. Software component search. Journal of Systems integration, 6:93{134, September 1996.
2. H. Mili, F. Mili, and A. Mili. Reusing software: Issues and research directions. IEEE Trans. on Software engineering, 21(6):528{562, June 1995.
3. S. Robertson and J. Robertson. Mastering the Requirement Process. Addison-Wesley, 1999.
4. A. M. Zaremski and J. M. Wing. Signature matching: A tool for using software libraries. ACM Trans. on Software Engineering and Methodology, 4(2):146{170, April 1995.
5. A. M. Zaremski and J. M. Wing. Specification matching of software components. ACM Trans. on Software Engineering and Methodology, 6(4):333{369, Oct 1997.
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