ABSTRACT

This paper describes the structure and components of a case-based scheduler named CBS-1 which is being created to demonstrate the feasibility and utility of case-based reasoning (CBR) for dynamic job-shop scheduling problems. The paper describes the characteristics of a specific real-world scheduling task used in the work on CBS-1, identifies major problems to consider, and gives arguments for and against the application of CBR. The functions of the components of the system are illustrated by examples. Finally, some existing case-based schedulers are compared with CBS-1.

INTRODUCTION

Scheduling is the allocation of resources, like machines or human power, to operations over time to achieve certain goals. In job-shop scheduling the goals to be achieved are the processing or production of discrete parts in several steps each requiring several different resources. Dynamic scheduling is scheduling simultaneously with the execution of the processes that are affected by the created schedules.

In the Interuniversitary Centre for CIM (IUCCIM) in Vienna the production process for remote controlled toy cars is used to demonstrate the main ideas in CIM. In this context the problem of scheduling incoming orders for toy cars into the ongoing production process arises. There are several reasons for the complexity of such a scheduling task.

• There is a combinatorial explosion of the number of possible schedules (which must be checked for feasibility) in each problem dimension such as the number of machines and operations.

• […]