1. A computer-implemented method and apparatus comprising: a. Definition Repository containing Object Schema, a graph of Objects and Relationships, which links user visible objects, called Context Object Types, with relevant services from multiple application and information systems; b. Context Object (CO) Client that displays a list of relevant services whenever a human user selects a Context Object wherein a service is relevant to Context Object if and only if all parameter objects of said service is reachable from selected Context Object by navigating paths in said Object Schema; c. Context Server and its subsystems, Context Subsystem and Domain Subsystem, that automatically determine input parameters of a relevant service and invoke said service, by navigating paths in said graph of Objects and Relationships between parameters of said relevant service and selected Context Object, wherein automatic determination of a parameter include retrieval of objects from their source applications during graph traversal; d. means for automatically propagating changes to all related objects whenever a service initiates changes to an origin object, wherein an object is related to said origin object if and only if said object is reachable from origin object in said graph of Objects and Relationships; whereby end-user of a composite application, has usability and productivity benefits including: i. he/she does not have to explicitly enter input data otherwise necessary to invoke a selected service, ii. a update to a Context Object automatically propagated to other objects including execution of services across multiple applications and information systems; and whereby developer creating composite applications out of existing services, gains productivity advantage including: iii. he/she does not have to explicitly program each path from a end-user visible Context Object of said composite application to said existing services, because the invented apparatus computes such a path from Object and Relationship graph.