Computer Integrated Manufacturing (CIM) is the study of manufacturing planning, integration, and implementation of automation. The Computer and Automation Systems Association of the Society of Manufacturing Engineers gives the following definition: ‘‘CIM is the integration of the total manufacturing enterprise through the use of integrated systems and data communications coupled with new managerial philosophies that improve organizational and personnel efficiency’’ (Singh 1996).

The outer layer represents general management and human resources management. The middle layer has three process segments: product and process definition, manufacturing planning and control, and factory automation. These segments represent all the activities in the design and manufacturing phases of a product life cycle, from concept to assembly. The center of the wheel represents the third layer, which includes information resources management and the common database.

The other view of CIM is the information view. As stated in the definition given by Digital Equipment Corporation, the objective of CIM implementation is to enable the right information to be sent to the right person at the right time. The information system plays a vital role in the operation of CIM. Although many kinds of activities are involved in managing a manufacturing company, each activity has a different function in business management and production control.

The associated function unit for the information system of CIM normally can be classified into three kinds of tasks: information collection, information processing, and information transfer.

Information collection is the basic function of an information system. The information collected forms the basis of decision making at different levels from business management to device control. There are many methods of information collection, depending on the information sources and technologies used. Device sensors may provide data regarding device status; barcode scanners may pro- vide data about the production status of online products; and form scanners and database table view interfaces may provide data about order, raw material purchasing, and user requirements. Some data may also come from e-mail systems. The data collected can be stored in different data formats and different repositories.

Information processing is closely related to the business functions of a company. Business functions range from strategy planning, process planning, product design, warehouse management, and material supply to production management and control. The upper-stream process data are processed by algorithms or human intervention and the instructions produced are used for the downstream process. In data processing, different decisions will be made. The decisions can be used to optimize the production processes or satisfy user requirements such as delivery time and quality requirements.

Information transfer between different function units has three main functions: data output from application software in a certain data format to a certain kind of data repository; data format transformation, and data transfer from one application to another application within the same computer or in a network environment.