Integration is the art of decomposition.
A growing demand for integrating stand-alone information systems with an HIS can be observed. Different forms of integration can be distinguished: technical integration, user interface integration, and integration of the information service. The integration of the information service appears to be especially difficult. An integrated information service can only be achieved when the applications use each other's information services. We will discuss three approaches for letting applications belonging to another system utilize the necessary information service of a host system. The first approach makes use of the user interface, and the necessary information service has to be extracted from the service to a user. Another, often used, approach is the extension of the applications with coupling modules. The coupling modules communicate messages and translate them into the context of the application. The applications are modified scarcely and the coupling modules have to supply the necessary information services. When the coupling problem is more complex (e.g., a larger set of data is to be exchanged interactively), a growing effort will be needed for these adapting modules. A better approach is to split the application into building blocks. Applications are composed of building blocks. The application, which should deliver the integrated information service, is also composed of such building blocks. The building blocks are designed to offer information services that can be used by other systems as well. If we succeed in decomposing the applications into suitable building blocks, an integrated information service could be more easily achieved.
van Poppel
B M
BM
BAZIS, Schipholweg 97, 2316 XA Leiden, The Netherlands.
Leguit
F A
FA
van der Marel
J
J
D006751:Hospital Information Systems; D007256:Information Systems; D011873:Radiology Information Systems; D018511:Systems Integration; D014584:User-Computer Interface