A framework for application systems engineering

Interactive Application Systems (IAS) attend to the information needs of application experts, i.e. problem-solving end-users within particular application environments. As such, IAS must be customized functionally and behaviourally toward both user and environment. Such customizing must be feasible in an economical fashion. The study claims that this objective is met by appropriate IAS development tools and by a basic IAS architecture that consists of the following main building blocks: a general-purpose dialogue processor that is controlled by a particular user interface specification, called information net; a library of software modules and packages for providing system functions on the basis of reusable software; and a data management system that may, just like the library elements, be procured from outside, perhaps even including an already existing information base. The paper discusses the approach in detail with particular emphasis on information nets and on the integration of reusable software into a total system. The paper argues that the approach is flexible enough to accommodate (rapid) prototyping, i.e. procuring of first versions of an IAS, that may be used during requirements analysis to refine the user wishes, or operationally during an interim period until the final system becomes available.