Process type

In operations, the design of the process is categorized into types for manufacturing and services. The choice of process design is most dependent on the volume and variety of the product or service that an organization offers. Each manufacturing or service operation can be characterized as one of the following: project, job shop, batch flow, line flow, or continuous flow. The nature of these processes is discussed below and summarized in the manufacturing product–process matrix of Hayes and Wheelwright, 1979 (Hayes and Wheelwright, 1979) (Figure 4).

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Figure 4 Product-Process Matrix, adapted from Hayes and Wheelwright, (1979)

3.3.1 Project Process

A project process is characterized by a high degree of job customization, a large scope for each project, and the release of substantial resources once a project is completed. Project processes lie at the high-customization, low-volume end of the process-choice continuum.

The sequence of operations and the processes involved in each one are unique to each project, creating one-of-a-kind products or services made specifically to customer order. Firms with project processes sell themselves on the basis of their capabilities, rather than on specific products or services. Projects tend to be complex, take a long time, and to be large. Many interrelated tasks must be completed, requiring close coordination. Projects typically make heavy use of certain skills and resources at particular stages, and then have little use for them for the rest of the time. A project process is based on a flexible flow strategy, with work flows redefined for each new project (Hayes and Wheelwright, 1979).

3.3.2 Job Shop Process

Next in the continuum of process choices is the job shop process. This creates the flexibility needed to produce a variety of products or services in significant quantities. Customization is relatively high and the volume for any one product or service is low. The work force and

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equipment are flexible and can handle various tasks. As with a project process, companies typically make products to order, and do not produce them ahead of time. Each order is handled as a single unit—as a job. A job shop process primarily involves the use of a flexible flow strategy, with resources organized around the process. Most jobs have a different sequence of processing steps (Hayes and Wheelwright, 1979).

3.3.3 Batch Flow Process

A batch flow process differs from the job process with respect to volume, variety, and quantity. The primary difference is that volumes are higher, because the same or similar products or services are provided repeatedly. Another difference is that a narrower range of products or services is provided. Variety is achieved more through an assemble-to-order strategy than through the make-to-order strategy of the job shop. Some of the components for the final product or service may be produced in advance. A third difference is that production lots or customer groups are handled in larger quantities (or batches) than they are with job shop processes. A batch of one product or customer group is processed, and then production is switched to the next one. Eventually, the first product or service is produced again. Batch flow processes have moderate volumes, but their variety is still too great to warrant dedicating substantial resources to each product or service. The flow pattern is jumbled, with no standard sequence of operations throughout the facility. However, more dominant paths emerge than at a job shop, and some segments of the process have a linear flow (Hayes and Wheelwright, 1979).

3.3.4 Line Flow Process

A line flow process lies between the batch and continuous processes: volumes are high and products or services are standardized, which allows resources to be organized around a product or service. Materials move linearly from one operation to the next, according to a fixed sequence, with little inventory held between operations. Each operation performs the same process over and over with little variability in the products or services provided.

Production orders are not directly linked to customer orders, as is the case with project and job processes. Manufacturers with line flow processes often follow a make-to-stock strategy, with standard products held in inventory so that they are ready when a customer places an order. This use of a line flow process is sometimes called mass production. However, the assemble-to-order strategy and mass customization are other possibilities that show line flow

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processes. Product variety is possible through careful control of the addition of standard options to the main product or service. The production may be either machine-paced or worker-paced (Hayes and Wheelwright, 1979).

3.3.5 Continuous Flow Process

A continuous process is the extreme end of high-volume, standardized production. It has rigid line flows and tightly linked process segments. Its name derives from the way materials move through the process. One primary material—such as a liquid, gas, wood fibers, or powder—

typically moves without stopping through the facility. The process often is capital-intensive and operates round the clock to maximize utilization and to avoid expensive shutdowns and start-ups (Hayes and Wheelwright, 1979).

These process structures differ in several respects such as flow, flexibility, number of products, capital investment, variable cost, labor content, and skill and volume. Figure 5 illustrates how the process characteristics vary with the structure.

Figure 5 Comparison of process structures and characteristics

The core of the process classification (Figure 4) is the so-called product–process matrix.

There is a tight connection between the nature of the product and the type of process used to produce it. This is generally true for health care, too: the nature of the process through which health care is delivered depends on the nature of care in terms of the structure of the problem solving. However, it would be dangerous to apply tools from production and assembly industries, such as the product–process matrix, without modification. Figure 6 shows a modified ‘product–process’ matrix from health care from Gemmel et al. (2013). As has been

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indicated, the nature of the service in health care is generally determined by the extent to which the underlying health care problem is structured. The nature of the service (structured versus unstructured health problems) determines the nature of the care process—that is, iterative versus sequential processes.

Figure 6 The Product-Process Matrix in health care, adapted from Gemmel et al. (2013)

3.4 Layout

In manufacturing, the facility layout consists of the configuration of the site with lines, buildings, major facilities, work areas, and other pertinent features, such as department boundaries. While the facility layout for services may be broadly similar to that for manufacturing, it also may be somewhat different. Because of its relative permanence, facility layout is probably one of the most crucial elements affecting efficiency. An efficient layout can reduce unnecessary material handling, help to keep costs low, and maintain product flow through the facility (Slack et al., 2009). The three basic types of layout are the product layout, the process layout, and the fixed-position layout. These layouts may be applied to either a single department or an entire facility (group of departments). Therefore, the elements of the

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layout may be either whole departments or individual pieces of equipment (such as hospital beds or pieces of cafeteria equipment). Understanding the difference between the layouts can give insight that can assist in the structuring of different operations.

3.4.1 Process layouts

Process layouts are found primarily in firms that produce customized, low-volume products that may require different processing requirements and sequences of operations. Process layouts are facility configurations in which operations of a similar nature or function are grouped together, arranging equipment according to its function. As such, they are occasionally referred to as functional layouts. Their purpose is to process goods or to provide services that involve a variety of processing requirements (Slack et al., 2009).

3.4.2 Product layouts

Product layouts are found in flow shops (repetitive assembly and process or continuous flow industries). Flow shops produce high-volume, highly standardized products that require highly standardized, repetitive processes. In a product layout, the resources are arranged sequentially, based on the routing of the products, and work units are moved along a line. In theory, this sequential layout allows the entire process to be laid out in a straight line, which at times may be totally dedicated to the production of only one product or product version. The flow of the line may then be subdivided so that labor and equipment are utilized smoothly throughout the operation (Slack et al., 2009).

3.4.3 Fixed-position layout

A fixed-position layout is appropriate for a product that is too large or too heavy to move. For example, battleships are not produced on an assembly line. For services, other reasons may dictate the fixed position (e.g., a hospital operating room where doctors, nurses, and medical equipment are brought to the patient) (Slack et al., 2009).

3.4.4 Combination layouts

Many situations call for a mixture of the three main layout types. These mixtures are commonly called combination or hybrid layouts (Slack et al., 2009).

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As in manufacturing, in health care, too, the basic goals in developing a facility layout should be functionality and cost savings. Functionality includes placing the necessary departments—

such as the operating and recovery rooms—close together. Functionality also involves keeping separate those departments that should not be located close together. The actual facility layouts applied to hospitals are almost always a mixture of the three basic types. A hospital may have an overall process layout, with all the departments grouped (intensive care, nursing units, administration). On the department level, there may be some product layouts (cafeteria, labs) and some fixed-position layouts (an operating room). The heterogeneity of the hospitals’ input (the iterative and sequential care processes) complicates the identification of the layout, resulting in only a handful of core processes in hospitals being optimized in their layout design—such as the surgery in the one-day clinic or a specialty cardiology department. Again, we claim that identifying and separating the care processes according to their sequential or iterative characteristics can result, for the former, in a product layout and, for the latter, in a process layout, thus enhancing efficiency.