KNOWLEDGE REPRESENTATION FOR PRELIMINARY STAGES OF ENGINEERING TASKS

Engineers make initial decisions when information is incomplete and when many goals are contradictory. The paper outlines a knowledge representation which supports explicit modelling of knowledge used during preliminary stages. The representation allows the formulation of two types of assumptions, defaults and preferences. Knowledge is categorized into three types, models (knowledge known before the engineering task begins), rules (knowledge which depends upon decisions made during the completion of a task), and control knowledge (knowledge related to search and conflict resolution, including knowledge of when to introduce rule clusters, called knowledge groups). Assumptions are accommodated within models and rules. When used with iterative reasoning strategies, such a representation provides valuable support, especially for situations in which durations of projects span many years.