Managing the Production Process in a Manufacturing Company
Operations managers engage in the daily activities of materials management, which encompasses the activities of purchasing, inventory control, and work scheduling.
Purchasing and Supplier Selection
The process of acquiring the materials and services to be used in production is called purchasing (or procurement). For many products, the costs of materials make up about 50 percent of total manufacturing costs. Not surprisingly, materials acquisition gets a good deal of the operations manager’s time and attention. As a rule, there’s no shortage of vendors willing to supply materials, but the trick is finding the best suppliers. Operations managers must consider questions such as:
- Can the vendor supply the needed quantity of materials at a reasonable price?
- Is the quality good?
- Is the vendor reliable (will materials be delivered on time)?
- Does the vendor have a favourable reputation?
- Is the company easy to work with?
Getting the answers to these questions and making the right choices—a process known as supplier selection—is a key responsibility of operations management.
Technology has changed the way businesses buy things. Through modern procurement, companies use the Internet to interact with suppliers. The process is similar to the one you’d use to find a consumer good—say, a high-definition TV—over the Internet. To choose a TV, you might browse the websites of manufacturers like Sony then shop prices and buy at Amazon, the world’s largest online retailer.
If you were a purchasing manager using the Internet to buy parts and supplies, you’d follow basically the same process. You’d identify potential suppliers by going directly to private websites maintained by individual suppliers or to public sites that aggregate information on numerous suppliers. You could do your shopping through online catalogs, or you might participate in an online marketplace by indicating the type and quantity of materials you need and letting suppliers bid. Finally, just as you paid for your TV electronically, you could use a system called electronic data interchange (EDI) to process your transactions and transmit all your purchasing documents.
The Internet provides an additional benefit to purchasing managers by helping them communicate with suppliers and potential suppliers. They can use the Internet to give suppliers specifications for parts and supplies, encourage them to bid on future materials needs, alert them to changes in requirements, and give them instructions on doing business with their employers. Using the Internet for business purchasing cuts the costs of purchased products and saves administrative costs related to transactions. It’s also faster for procurement and fosters better communications.
If a manufacturer runs out of the materials it needs for production, then production stops. In the past, many companies guarded against this possibility by keeping large inventories of materials on hand. It seemed like the thing to do at the time, but it often introduced a new problem—wasting money. Companies were paying for parts and other materials that they wouldn’t use for weeks or even months, and in the meantime, they were running up substantial storage and insurance costs. If the company redesigned its products, some parts might become obsolete before ever being used.
Most manufacturers have since learned that to remain competitive, they need to manage inventories more efficiently. This task requires that they strike a balance between two threats to productivity: losing production time because they’ve run out of materials and wasting money because they’re carrying too much inventory. The process of striking this balance is called inventory control, and companies now regularly rely on a variety of inventory-control methods.
One method is called just-in-time (JIT) production: the manufacturer arranges for materials to arrive at production facilities just in time to enter the manufacturing process. Parts and materials don’t sit unused for long periods, and the costs of “holding” inventory are significantly cut. JIT, however, requires considerable communication and cooperation between the manufacturer and the supplier. The manufacturer has to know what it needs and when. The supplier has to commit to supplying the right materials, of the right quality, at exactly the right time.
Material Requirements Planning
A software tool called material requirements planning (MRP), relies on sales forecasts and ordering lead times for materials to calculate the quantity of each component part needed for production and then determine when they should be ordered or made. The detailed sales forecast is turned into a master production schedule (MPS), which MRP then expands into a forecast for the needed parts based on the bill of materials for each item in the forecast. A bill of materials is simply a list of the various parts that make up the end product. The role of MRP is to determine the anticipated need for each part based on the sales forecast and to place orders so that everything arrives just in time for production.