From legacy and client/server systems to components in healthcare information systems in Finland.
A strategy and toolset (FixIT) for migrating a specific type of legacy systems--based on the FileMan DBMS of the U.S. Department of Veterans Affairs--to a two-tier client/server and web browser-based architecture was presented in MEDINFO'98. In the current paper we discuss the further migration to a multitier software component architecture. A literature survey and industry contacts were used to specify an open, component-based target architecture for healthcare information systems to be reached by the year 2005, as well as a phased migration strategy from the present FileMan/FixIT-based systems towards the target. The target architecture is based on large-grained business components and accommodates heterogeneous elements on the intra-component, intra-application, intra-organization and inter-organizational levels. Four logical tiers are identified within a business component. Three migration paths are specified for different cases: the tier-by-tier, piece-by-piece, and web-wrapping paths. It is argued that the architecture, supported by off-the-shelf toolsets, application frameworks and a new software development process, makes it possible to turn legacy systems into a valuable asset, split monolithic applications into reusable components, and ultimately replace the legacy parts at a feasible pace
Mykkänen
J
J
Computing Centre, University of Kuopio, 70211 Kuopio, Finland. Juha.Mykkanen@uku.fi
Korpela
M
M
Eerola
A
A
Porrasmaa
J
J
Ruonamaa
H
H
Sormunen
M
M
D003628:Database Management Systems; D005387:Finland; D006751:Hospital Information Systems / Q000639:trends*; D012984:Software / Q000639:trends*; D012985:Software Design