Manufacturing Support Systems

MANUFACTURING SUPPORT SYSTEMS

To operate the production facilities efficiently, a company must organize itself to design the processes and equipment, plan and control the production orders, and satisfy product quality requirements. These functions are accomplished by manufacturing support systems – people and procedures by which a company manages its production operations. Most of these support systems do not directly contact the product, but they plan and control its progress through the factory.

Manufacturing support involves a cycle of informationprocessing activities, as illustrated in Figure 1.5. The production system facilities described in Section 1.1 are pictured in the center of the figure. The informationprocessing cycle, represented by the outer ring, can be described as consisting of four functions: (1) business functions, (2) product design,

(3) manufacturing planning, and (4) manufacturing control.

Business Functions. The business functions are the principal means of communicating with the customer. They are, therefore, the beginning and the end of the informationprocessing cycle. Included in this category are sales and marketing, sales forecasting, order entry, cost accounting, and customer billing.

The order to produce a product typically originates from the customer and proceeds into the company through the sales and marketing department of the firm. The production order will be in one of the following forms: (1) an order to manufacture an item to the customer’s specifications, (2) a customer order to buy one or more of the manufacturer’s proprietary products, or (3) an internal company order based on a forecast of future demand for a proprietary product.

Product Design. If the product is to be manufactured to customer design, the design will have been provided by the customer. The manufacturer’s product design department will not be involved. If the product is to be produced to customer specifications, the manufacturer’s product design department may be contracted to do the design work for the product as well as to manufacture it.

If the product is proprietary, the manufacturing firm is responsible for its development and design. The cycle of events that initiates a new product design often originates in the sales and marketing department; the information flow is indicated in Figure 1.5. The departments of the firm that are organized to accomplish product design might include research and development, design engineering, drafting, and perhaps a prototype shop.

Manufacturing Planning. The information and documentation that constitute the product design flows into the manufacturing planning function. The informationprocessing activities in manufacturing planning include process planning, master scheduling, requirements planning, and capacity planning. Process planning consists of determining the sequence of individual processing and assembly operations needed to produce the part.The manufacturing engineering and industrial engineering departments are responsible for planning the processes and related technical details.

Manufacturing planning includes logistics issues, commonly known as production planning. The authorization to produce the product must be translated into the master production schedule. The master production schedule is a listing of the products to be made, when they are to be delivered, and in what quantities. Months are traditionally used to specify deliveries in the master schedule. Based on this schedule, the individual components and subassemblies that make up each product must be planned. Raw materials must be purchased or requisitioned from storage, purchased parts must be ordered from suppliers, and all of these items must be planned so that they are available when needed. This entire task is called material requirements planning. In addition, the master schedule must not list more quantities of products than the factory is capable of producing each month with its given number of machines and manpower. A function called capacity planning is concerned with planning the manpower and machine resources of the firm.

Manufacturing Control. Manufacturing control is concerned with managing and controlling the physical operations in the factory to implement the manufacturing plans. The flow of information is from planning to control as indicated in Figure 1.5. Information also flows back and forth between manufacturing control and the factory operations. Included in the manufacturing control function are shop floor control, inventory control, and quality control.

Shop floor control deals with the problem of monitoring the progress of the product as it is being processed, assembled, moved, and inspected in the factory. Shop floor control is concerned with inventory in the sense that the materials being processed in the factory are workinprocess inventory. Thus, shop floor control and inventory control overlap to some extent. Inventory control attempts to strike a proper balance between the danger of too little inventory (with possible stockouts of materials) and the carrying cost of too much inventory. It deals with such issues as deciding the right quantities of materials to order and when to reorder a given item when stock is low.

The mission of quality control is to ensure that the quality of the product and its components meet the standards specified by the product designer. To accomplish its mission, quality control depends on inspection activities performed in the factory at various times during the manufacture of the product. Also, raw materials and component parts from outside sources are sometimes inspected when they are received, and final inspection and testing of the finished product is performed to ensure functional quality and appearance.