The two process categories—intermittent and repetitive—can be further divided to provide greater detail. Intermittent processes can be divided into project processesand batch processes. Repetitive processes can be divided into line processes and continuous processes. This provides a continuum of process types as shown in Figure 5.8.
1. Project processesare used to make one-of-a-kind products exactly to cus- tomer specifications. These processes are used where there is high custom- ization and low product volume, as each product is different. Examples include construction, shipbuilding, medical procedures, custom tailoring, and interior design.
2. Batch processesare used to produce small quantities of products in groups or batches based on customer orders or product specifications. They are also 136 Operations Management
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known as job shops. The volumes of each product produced are still small, and there can still be customization. Examples can be seen in bakeries, edu- cation, and printing shops. The classes you take at the university use a batch process.
3.Line processes are designed to produce a large volume of a standardized product for mass production. They are also known as flow shops, flow lines, or assembly lines. With line processes the product that is produced is made in high volume with little or no customization. Think of a typical assembly line that produces everything from cars, computers, television sets, shoes, candy bars, even food items.
4.Continuous processes operate continually to produce a very high volume of a fully standardized product. Examples include oil refineries, water treatment plants, and certain paint facilities. The products produced by continuous processes are usually in continual rather than discrete units such as liquid or gas. They usually have a single input and a limited number of outputs. Also, these facilities are usually highly capital intensive and automated.
Note that both project and batch processes have low product volumes and offer customization. The difference is in the volume and degree of custom- ization. Project processes are more extreme cases of intermittent processes, compared to batch processes. Also, note that both line and continuous processes primarily produce large volumes of standardized products. Similarly, continuous processes are more extreme cases of high volume and product standardization than are line processes.
FIGURE 5.8
Continuum of process types.1
Low 1. Project process (customer job shop;
construction) Intermittent processes 2. Batch process
(education classes;
bakery; printing shop)
3. Line process (assembly lines;
cafeteria) Repetitive
processes 4. Continuous processes
(oil refinery;
water treatment plant)
High Product volume
High Low
Product standardization
1Robert H. Hayes, and Stephen C. Wheelwright, ‘‘Link Manufacturing Process and Product Life Cycles.’’
Harvard Business Review, January–February 1979: 133–140.
Process Design 137 www.freebookslides.com
Figure 5.8 positions these four process types along the diagonal to show the best process strategies relative to product volume and product customization.
Companies whose process strategies do not fall along this diagonal may not have made the best process decisions. Keep in mind, however, that not all processes fit into only one of these categories: a company may use both batch and project processing to good advantage. For example, a bakery that produces breads, cakes, and pastries in batches may also bake and decorate cakes to order. Also, today’s advances in technologies have created greater processing options. For example,
M A N A G E R I A L I N S I G H T S B O X — A N E W M A N U F A C T U R I N G P R O C E S S
Rapid Manufacturing
It is always a challenge for companies to identify business processes that truly provide a competitive edge. Now there is one approach that seems to offer such a solution. It is a concept known as rapid manufacturing (RM) and uses technology to make products to order when needed, exactly where they are needed and is considered to be one of the most important potential influences on the future of manufacturing.
RM involves the economic manufacture of low-volume products on demand at multiple locations near the point of consumption. It relies on new developments in three-dimensional (3D) printing technologies and a process known as additive layer manufacturing (ALM). ALM consists of three basic steps. First, a 3D computer representation is fed into a specially designed layer manu- facturing machine, which can come from a variety of sources including computer-assisted design (CAD). Next, the image is digitally sliced up into hundreds of two-dimensional layers, each representing a profile of the part to be manufactured. Finally, the layers are rebuilt inside the ALM machine one at a time, from the bottom up, until the part is complete.
There has been a rapid rise in the number of companies using RM. Companies such as Boeing, Airbus, BAE Systems, Renault, and Honda are all using RM for a variety of applications. Also, healthcare has many applications as well. For example, RM is being used to manufacture bone- replacement material for reconstructive surgeries and for creating customized prosthetics. RM is also used to design disposable surgical cutting guides, which are personalized to the individual patient.
Dentistry is one of the best-known applications for RM; doctors are using the technology to manufacture customized dental caps, bridges, and crowns. Also, it is used in the production of personalized in-the-ear hearing aids, which are manufactured to fit exactly into each patient’s ear.
Another example is the manufacture of invisible dental braces. Invisalign Inc. is a company that uses RM to manufacture forming tools over which disposable, transparent dental braces are individually formed in sets for each patient.
Adapted from: Reeves, Phil. ‘‘How Rapid Manufacturing could Transform Supply Chains.’’ CSCMP’sSupply Chain Quarterly, Quarter 4, 2008.
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many companies are moving toward mass customization, which provides incre- ased variety while still getting the advantages of repetitive processes. Consider companies such as Dell that allows customers to design their own computer online, or Nike their own footwear. Here customers can ‘‘design’’ a product by choosing from a range of options. Mass customization uses advanced technol- ogies to customize products quickly and at a low cost. These companies store inventory in standard modules that are then configured to the exact product specification desired by the customer.