High-level design for user and component interfaces

Component-based software architecture is very important for current software engineering practice because (a) it is the basis for re-use of software at the component level, and (b) in distributed systems, the physical distribution of an application over separate computers represents a decomposition of the application. Typical e-commerce applications consist of various components sometimes belonging to different organizations, and presenting different user interfaces to various categories of users. We review in this paper the current trend in standards for inter-component communication in distributed systems, including various forms of remote procedure calls (RPC) and message passing, and paradigms for describing and implementing user interfaces in the Web environment. We discuss whether the user interface can also be described, at an abstract level, by RPC primitives. In the second part of the paper, we discuss the importance of indicating which party is responsible for making certain decisions for selecting control flow alternatives and certain parameter values. This leads to some guidelines for describing system behavior scenarios at the requirements level. We also discuss how this approach can be integrated with screen-oriented behavior definitions.