June 1998 CHAIMS1 Challenge 1: Composition of Processes... versus composition and integration of Data »data-warehouses »wrapping data available on web versus composition of Components »reusing small components via copy/paste or shared libraries locally installed »large distributed components within same “domain” as composition, e.g. within one bank or airline CHAIMS: » processed information provided by megamodules » composing autonomous execution threads

June 1998 CHAIMS2 Local Components, Remote Data Domain expert Client computer Control & Computation Services I/O a b c d e Wrappers to resolve differences I/O Data Resources

June 1998 CHAIMS3 Remote Computational Components Domain expert Client workstation Computation Services IO module MEGA modules IO module a b c d e Data Resources Sites R T SU T C

January 1999 CHAIMS4 Challenge 2: Autonomy Megamodules are autonomous: »responsibility for maintenance is with provider »client has no direct control over availability of services and resources provided »client might be able to choose from several providers »heterogeneity concerning implementation languages, interface definitions (onthologies), server platforms and distribution systems ==> many advantages, yet access protocols and composition environments have to take these issues into account Megamodule A at site Stanford provided by InfoLab Megamodule B at site SLAC provided by Admin Megamodule C at site NewCom provided by BestCalc

June 1998 CHAIMS5 Challenge 3: Heavy-weight Services What we need: ==> monitoring progress of a service ==> possibility to choose among equivalent services based on estimated waiting time and fees ==> parallelism among services ==> preliminary overview results, choosing level of accuracy / number of results for complex processes ==> novel optimization techniques Services are not free for a client: execution time of a service transfer time for data fees for services

June 1998 CHAIMS6 Challenge 4: Non-technical Domain Experts “Composer”: »is domain expert of domain that uses these services »is not technical expert of middleware system or experienced programmer, »wants to focus on problem at hand (=results of using a megaprogram) »e.g. scientist, assistant of a general Company providing services: »domain experts of domain of service (e.g. weather) »technical experts for wrapping services, setting up servers in a middleware system »marketing experts

June 1998 CHAIMS7 Challenge 5: Purely Compositional Language Possible? Which languages did succeed? –Algol, ADA: integrated composition and computation –C, C++: focus on computation Why new language? –complexity: not all facilities of a common language (compare to approach of Java), –inhibiting traditional computational programming (compare C++ and Smalltalk concerning object-oriented programming) –focus on issue of composition, parallelism by asynchrony, and optimization