Compositional Specification Calculus for Information Systems Development

The paper presents a novel approach for type speciication manipulations as the basic operations intended to develop various forms of compositions in information systems. Among them are interoperable compositions of pre-existing components formed during the information systems design, heterogeneous multidatabase compositions, database sche-ma and ontology integration, compositions of workkows, compositions of the type of the result of algebraic operations over typed data collections. In the paper the compositional speciication calculus is presented in context of one of such application { the compositional information systems development. Principle of decomposition of type speciications into a collection of type reducts serving as units of reuse and composition is formulated. An operation of taking most common reduct for component and speciication of requirements types is deened. The reenement property of the common reduct leads to a justiiable identiication of reusable component fragments. Type lattice and algebra based on partially ordered set of complete type speciications and the type common-ality principle are deened. Type speciication composition operations of the algebra are based on identiication of common information in the composed speciications. Paper presents a combination of semi-formal and formal modeling facilities to perform provably correct operations of common reduct identiication, type speciication composition and reuse.