An Environment for Developing Planning Support Expert Systems

Abstract

Planning is one of the most important tasks in business. Planners have conceptual models of business and knowledge ; these models consist of (1) factors that are represented as numerical values by abstracting certain elements of business, and (2) the constraints that these factors must satisfy. The goal of planning is to decide the values of the factors that satisfy all constraints. However, it is difficult to define all constraints and knowledge rigidly, because planners are not explicitly Conscious of them all. There are some that they never perceive until they are confronted with particular situations. Therefore, it is very difficult to develop systems that generate plans automatically. By representing explicitly definable parts of conceptual models and knowledge in the systems, we can develop expert systems to generate plans that satisfy only defined constraints. We refer to these systems as planning support expert systems (PSESs). PSESs cooperate with the planners in making plans. Planners are the best people to develop PSESs. To do so, they require planning environments in which they can develop the systems without programming, because they are not usually experts in this. All that should be required of them is to define their conceptual models and knowledge. Therefore, planning environments should provide mechanisms to generate plans that satisfy all defined constraints, and user interfaces that allow interaction between the systems and planners. Inspire is a planning environment based on the above idea. Numerical factors, equality constraints among factors, and dependencies among them are defined as models in the system, and other constraints and knowledge about how to satisfy them are defined as rules in knowledge bases. Inspire provides an algorithmic constraint satisfier to satisfy all equality constraints automatically, and uses defined rules to satisfy other constraints. It also provides a spreadsheet-type interface. As a result, planners can develop PSESs in Inspire without programming.