Knowledge-Based Design

We tend to visualize design as a problem solved by the solitary activity of an individual. However, there are actually two design problems: “Design-in-the-Small” (DITS) and “Design-in-the-Large” (DITL). Design-in-the- Small describes the activities of a single engineer or small group who select components, determine parameters, perform analyses, etc. In reality, this represents only a fraction of the overall design task. Most of the effort, and expense, is in “Design-in-the-Large”. Many artifacts, including those produced by the project’s participating corporations, are so complex that the designs require the efforts of many engineers. This means that the artifact must be functionally and/or physically decomposed, and the pieces divided amongst groups of engineers. The major issue in “Design-in-the-Large” is how to achieve high levels of collaboration among engineers. That is, how each engineer’s design task can be managed so that it integrates well with the results of others. Collaboration among design teams is necessary because each part of a design constrains the others. A change in one part has a “domino effect” on other portions of the design. Unfortunately, changes occur frequently during the course of design, so that each engineer must continually revise his work.

Why are changes so frequent? Design is an evolutionary process, with each new step uncovering unexpected problems and subtleties. Initial assumptions become invalid, leading to the negotiating of proposed changes and the creation of new tasks. Moreover, customers continually redefine their goals in midstream. Budgets and perceived markets change and customers begin to verbalize requirements which had previously been only implicit. Finally, advances in technology offer solutions not previously possible. Regardless of source, change is complex and difficult to manage. Project management has traditionally been centralized. Information tends to be used at the start of a project, to identify the critical path, and to rationalize deviations after they occur. Project management, however, has traditionally been less important in coordination of day to day activities. Companies that produce highly technical products requiring a diversity of engineering skills are finding that the time compression imposed by the market place has pushed their management skills to the wall – their old ways of managing engineering projects are just not good enough. By pushing for greater levels of concurrency, management is experiencing increased problems at the interface of engineering groups. The University of Toronto’s Enterprise Integration Laboratory and Spar Aerospace’s Advanced Technology Systems Group are collaborating to create a Knowledge Aided Design (KAD) system for supporting Design-in-the-Large (DITL). The objective of the Design-in-the-Large project is to increase engineering quality and reduce engineering time for multi-person engineering projects.

We are approaching the DITL problem by using knowledge-based information technologies to enhance the degree of awareness, understanding, cooperation, and coordination among engineering team members. There are two factors that are critical to the success of this project. First is the unintrusive acquisition of design information and decisions; it is clear that acquiring design information/decisions is very difficult – most engineers do not “design with” computers. If information technology is to be a design process participant, then we must address the barriers to the adoption of technology by end users. Consequently, a major focus on this research will be on the role of “electronic engineering notebooks” in the capture, storage and dissemination of design information and decisions, and on their role in integrating and managing design decisions and processes.

The second factor is the types of collaboration services to provide that would both aid the design process and entice engineers into using the technology. Towards this end, we focusing on two services: 1) the creation of an Integrating Knowledge Base (IKB) with supporting access and maintenance functions to provide engineers with the ability to find and/or be informed of information and knowledge of relevance to their task, and 2) the creation of a Technical Interface Management system (TIM) that models and manages the technical problems that arise at the interface among engineering groups. For example, the impact that design decisions made by one group affect another, and the requirements that are not satisfied because they fall in between their interests.

This report describes the research necessary to develop a Knowledge-Aided Design system to support Design-in-the-Large. The uniqueness of this research stems from its position at the intersection of many of the fields and technologies described above: Cooperative Work, Coordination Theory, Distributed Artificial Intelligence, Engineering Databases, Notebooks, Organization Behavior and Concurrent Engineering, and being situated in a real engineering environment where the stresses and strains of providing useful solutions will probably force the research in unanticipated directions. A central concern of ours is that engineers will not automatically adopt technologies created for them by researchers because, all too often, these are theoretically sound but practically useless, or do not fit the methods the engineer is using [Grading 88]. Our goal is to create a design system that is both technically advanced and usable by engineers. Therefore our planning philosophy has been to first adapt technology to engineering practices, then motivate engineers to modify engineering practices to enhance quality and productivity. The following describes our proposed research in the context of a plan that implements this philosophy in a series of phases whose time span exceeds the 3-year duration of this initial project.