Computer Aided Manufacturing(CAM)
Computer Aided Manufacturing(CAM): The computer aided manufacturing implies manufacturing itself, aided or controlled by computers. In a wider sense, it denotes all the activities in the manufacturing environment like use of computers in inventory control, project management, material requirement planning, data acquisition, testing and quality control. Improved reliability in view of the better manufacturing methods and controls at the manufacturing stage, the products thus manufactured as well as of the manufacturing system would be highly reliable. Since most of the components of a CAM system would include integrated diagnostics and monitoring facilities, they would require less maintenance compared to the conventional manufacturing methods. Because of the Computer Numerical Control (CNC) machines used in production and the part programs being made by the stored geometry from the design stage, the scrap level would be reduced to the minimum possible and almost no rework would be necessary. Since all the information and controlling functions are attempted with the help of the computer, a better management control on the manufacturing activity is possible. All the above advantages when properly translated, would mean a lower total cost and consequently, higher final earnings. Therefore any manufacturing activity in a production unit (job shop production or mass scale manufacture) can get the benefits of Computer Aided Manufacturing. However, better results can be obtained when the design and manufacturing activities are properly integrated. Also, when there is a large variety of products or minor changes required in the existing production programme, CAM can easily manage the necessary changes or alterations. Following are the main advantages of using CAM.
- Greater design freedom Any changes that are required in design can be incorporated at any design stage without worrying about any delays, since there would hardly be any in an integrated CAM environment.
- Increased productivity In view of the fact that the total manufacturing activity is completely organized through the computer, it would be possible to increase the productivity of the plant.
- Greater operating flexibility CAM enhances the flexibility in manufacturing methods and changing of product lines.
- Shorter lead time Lead times in manufacturing would be greatly reduced. The integration of CAD and CAM systems is called Computer Integrated Manufacturing (CIM) system. The role of computer in manufacturing may be in two major groups namely computer monitoring and control of the manufacturing process and manufacturing support applications, which deal essentially with the preparations for act of manufacturing and post manufacture operations. Computers are used in controlling machine tools and other material handling equipments.
KINDS OF PRODUCTION SYSTEMS: The choice of production type dictates the machine requirements, organizational system to a large extent, layout planning and inventory subsystems. Three main types of production are job, batch and flow or process production. The simplest way is to classify based on production
and processes by lot size, namely single unit production, small lot production, moderate lot production, large lot production, and continuous production. The second classification comprises three categories, namely small size production of a large variety of products, medium-scale production of a limited range of products, and a large-scale production of a small variety of products. Obviously, this method is related to the number of product types and production lot
sizes, and is an effective means of analyzing modern production management. The third classification is related to the size of the production system expressed through the number of employees or the amount of fixed assets involved, namely small production unit employing less than 30 employees, medium-small having 30 to 300 employees, medium with 301 to 2,000 employees and large with 2001 to 15,000 employees, and a giant corporation employing more than 15,000 employees Job shop production deals the manufacture of very small lots, often of single jobs. This may be required in special situations for the purpose of proving a design, making prototypes, in tool making or for special purpose applications. In view of the very small lot, no special
purpose machines or tooling can be economically justified. Hence, the manufacturing has to be carried on with the general purpose machines and tooling, which is a very lengthy and often an error prone process.
MANUFACTURING SYSTEM: Manufacturing basically implies making of goods or articles and providing services to meet the needs of mankind. It creates value by useful application of physical and mental-labor in the process. It is a chain of interrelated activities of production process and other support services activities of an manufacturing environment such as order processing, product design, design and manufacturing of tools, die, mould, jigs, fixtures and gauges, selection of material, planning, managing and maintaining control of the processes, production, and reliable quality of processed product in a systematic and sequential manner with proper coordination, cooperation and integration of the whole manufacturing system that will lead to economical production and effective marketing of proposed product in the minimum possible time. It is, therefore, evident that manufacturing today is not a one man activity as it was in the initial stages, wherein all the physical and mental inputs were applied by a single craftsman. These days it has become totally a team work which consists of several components interacting together in a dynamic manner. This entire domain of manufacturing is known as Manufacturing System, which takes the required inputs and delivers the products for the customer. It is, therefore, evident that manufacturing today is not a one man activity as it was in the preliminary stages, wherein all the physical and mental inputs were provided by a single workman. Today it is a team work which consists of several components interacting together in a dynamic manner to provide the required physical and mental inputs at appropriate stages to impart desired results. This entire domain of manufacturing is known as Manufacturing System, which takes the required inputs and delivers the products for the customer. Manufacturing system requires a large number of activities, few independent and rests mostly interrelated. The manufacturing activities in a manufacturing system jointly contribute towards economic and qualitatively acceptable production of desired articles in minimum possible time. As per the need of the customer, the products are identified and their demands are determined roughly for market forecast by considering present and future competition. Products that may render the desired service over its expected life satisfactorily as per requirement of customers are identified in terms of their demand, conceived and developed for securing orders by the sales department. Once the product design activity is over and the design finalized from all angles, functional, aesthetic, material selection, safety, economy, etc., it is followed by preparation of production drawings of the product assembly and its components including a bill of materials. This is the stage where a make or buy decision has to be taken in order to decide as to which components are to be bought from outside and which are to be manufactured within the concern. It is followed by process planning i.e. selection of the best process and an its parameters, design of jigs, fixtures and dies, selection of tooling, programming of tool path as per need, for the components to be produced in-house. An important activity in process planning within the organization is also to involve latest research and development findings, through which the old processes are improved and new one’s are developed in order to ensure better quality and economic production. The interaction of different manufacturing activities in a manufacturing system can also be further enhanced by the use of computer and hence leading CIM. The real manufacturing or production activity is carried out on the shop. The layout of the shop floor has a significant influence on the tools required to be coordinated in order to an economical and high quality production of various components. It should be such that it ensures timely movement of raw materials, dies moulds, jigs and fixtures and finished components, adequate safety to men, material and machinery, enables timely inspection and quality control and minimizes handling time for material and parts, etc. During actual manufacturing a lot of different activities are called management function. Various engineers play an important role in the organizational function of a manufacturing concern. They are required to ensure proper movement of the material, tools and parts as per their specialized jobs in industry.