A tool for development of qualitative and approximate quantitative process models

Abstract

A methodology and a tool to support the early stages of model development is presented. The model development basis is conservation of extensive thermodynamical properties, called quantities. The conceptual basis for the graphical editor layout is description of dynamic interactions between process quantities and interactions from the environment in a so called DYnamic QUantity Interaction Diagram (DYQUID). The DYQUID model representation forms a superset of a large number of dynamic process model representations, such as locally linear model structures, qualitative differential equations and conventional nonlinear state space models. The prototype version of the editor is object oriented, and is written in C++. The editor works with objects which fit engineering notions. Each object has its graphical representation. The editor is equipped with generic function types for transfer and reaction mechanisms. The editor may be expanded with additional function types suitable for a pertinent application area. The editor is interactive, driven by menus and questionnaires. One purpose of this experimental version of a DYQUID editor is to obtain experience with the efficiency of the user interface for facilitating development of different types of mutually consistent model representations.