What is Computer Integrated Manufacturing (CIM)?

Computer Integrated Manufacturing is a term to describe complete automation with all processes functioning under computer control. It uses the database and communication technologies to integrate the design, manufacturing and business functions that combine the automated segment of factory or facility. CIM reduces the human component of manufacturing and thereby relieves the process of its most expensive and error-prone ingredient. CIM stands for a global methodological approach in the enterprise in order to improve the industrial performances.

This methodological approach is applied to all activities from the design of the product until its delivery (and sales support) in an integrated way, using various methods, means and techniques in order to secure simultaneously production improvement, cost reduction, fulfillment of delivery dates, quality improvement and global and local flexibility of manufacturing system. CIM means all those associated with a company should involve totally in the process of product development and manufacture. In such a methodological approach economic, social and human aspects have the same importance as technical aspects.

Nature of CIM System

CIM makes use of the full range of the capabilities, the digital computer holds for manufacturing. The computer has unique potential to provide manufacturing with two powerful capabilities, namely on-line variable program (flexible) automation and on-line moment-by-moment (optimization real time).

The computer has the capability to do the above for hard components of manufacturing (the manufacturing machinery and equipment) and soft component of manufacturing (the information flow, the database, and so on). In addition computer has capability to do the above not only for the various bits and pieces of manufacturing activity but also for the entire system of manufacturing. Therefore computer has the tremendous potential to integrate the entire system and thereby evolve the computer integrated manufacturing system.

Types of Manufacturing Systems

The term "Manufacturing" covers a broad spectrum of activities. Metal working industries, process industries like chemical plants, oil refineries, food processing industries, electronic industries making microelectronic components, printed circuit boards, computers and entertainment electronic products etc., are examples of manufacturing industries. Manufacturing involves fabrication, assembly and testing in a majority of situations. However, in process industries operations are of a different nature. Manufacturing industries can be grouped into the following categories

(a) Continuous Process Industries. In this type of industry, the production process generally follows a specific sequence. These industries can be easily automated and computers are widely used for process monitoring control and optimization. 

(b) Mass Production Industries.  Industries manufacturing fasteners (nuts, bolts etc), integrated chips, automobiles, entertainment electronic products, bicycles, bearings etc. are all mass produced. Production lines are specially designed and optimized to ensure automatic and cost effective operation. Automation can be either fixed type or flexible.

(c) Batch production. The largest percentage of manufacturing industries is involved in batch production. The distinguishing feature of this type of production is the small to medium size of the batch, and varieties of such products to be taken up in a single shop. Due to the variety of components handled, work centers should have wider specifications. Another important fact is that small batch sizes involve loss of production time associated with product changeover.

As mentioned earlier, integration of computer in process industries for production automation, process monitoring and control and optimization is relatively easy. In the case of mass production and batch production computer integration faces a number of problems as there are a large number of support activities which are to be tied together.

Automation in the actual production has been implemented using different techniques since the turn of the 20th century. Fixed automation using mechanical, electrical, pneumatic and hydraulic systems are widely used in automobile transfer lines. This type of automation has a severe limitation -the lines are designed for a particular product and any product change will require extensive modifications to the line.

The concept of programmable automation was introduced later. These were electrically controlled systems and programs were stored in punched cards and punched tapes. Development of digital computers, microelectronics and microprocessors really altered the automation scenario during 1950-1990. Machinery control is now designed around microprocessors and microelectronics is part and parcel of industrial drives. The need to meet the design and manufacturing requirements of aerospace industries after the Second World War necessitated the development of two distinct technologies - CAD and CAM.