Plant management

Customized product. If the customer requires a one-of-a-kind item with unique

features, manual labor has the advantage as the appropriate production resource

because of its versatility and adaptability. Humans are more flexible than any automated machine.

• Ups and downs in demand. Changes in demand for a product necessitate changes in

production output levels. Such changes are more easily made when manual labor is

used as the means of production. An automated manufacturing system has a fixed

cost associated with its investment. If output is reduced, that fixed cost must be

spread over fewer units, driving up the unit cost of the product. On the other hand,

an automated system has an ultimate upper limit on its output capacity. It cannot

produce more than its rated capacity. By contrast, manual labor can be added or

reduced as needed to meet demand, and the associated cost of the resource is in direct proportion to its employment. Manual labor can be used to augment the output

of an existing automated system during those periods when demand exceeds the

capacity of the automated system.

• Need to reduce risk of product failure. A company introducing a new product to the

market never knows for sure what the ultimate success of that product will be. Some

products will have long life cycles, while others will be on the market for relatively

short periods. The use of manual labor as the productive resource at the beginning

of the product’s life reduces the company’s risk of losing a significant investment in

automation if the product fails to achieve a long market life. Section 1.4.3 discusses

an automation migration strategy that is suitable for introducing a new product.

• Lack of capital. Companies are sometimes forced to use manual labor in their production operations when they lack the capital to invest in automated equipment.

1.3.2 Labor in Manufacturing Support Systems

In manufacturing support functions, many of the routine manual and clerical tasks can

be automated using computer systems. Certain production planning activities are better accomplished by computers than by clerks. Material requirements planning (MRP,

Section 25.2) is an example. In material requirements planning, order releases are generated for component parts and raw materials based on the master production schedule

for final products. This requires a massive amount of data processing that is best suited

to computer automation. Many commercial software packages are available to perform

MRP. With few exceptions, companies that use MRP rely on computers to perform the

computations. Humans are still required to interpret and implement the MRP output and

to manage the production planning function.

In modern production systems, the computer is used as an aid in performing virtually

all manufacturing support activities. Computer-aided design systems are used in product

design. The human designer is still required to do the creative work. The CAD system is a

tool that augments the designer’s creative talents. Computer-aided process planning systems are used by manufacturing engineers to plan the production methods and routings.

In these examples, humans are integral components in the operation of the manufacturing

support functions, and the computer-aided systems are tools to increase productivity and

improve quality. CAD and CAM systems rarely operate completely in automatic mode.

Humans will continue to be needed in manufacturing support systems, even as the

level of automation in these systems increases. People will be needed to do the decision making, learning, engineering, evaluating, managing, and other functions for which

humans are much better suited than machines, according to Table 1.1. Even if all of the

manufacturing systems in the factory are automated, there is still a need for the following

kinds of work to be performed by humans:

• Equipment maintenance. Skilled technicians are required to maintain and repair the

automated systems in the factory when these systems break down. To improve the reliability of the automated systems, preventive maintenance programs are implemented.

• Programming and computer operation. There will be a continual demand to upgrade

software, install new versions of software packages, and execute the programs. It is anticipated that much of the routine process planning, numerical control part programming, and robot programming may be highly automated using artificial intelligence

(AI) in the future. But the AI programs must be developed and operated by people.

• Engineering project work. The computer-automated and integrated factory is likely

never to be finished. There will be a continual need to upgrade production machines,

design tooling, solve technical problems, and undertake continuous improvement

projects. These activities require the skills of engineers working in the factory.

• Plant management. Someone must be responsible for running the factory. There

will be a staff of professional managers and engineers who are responsible for plant

operations. There is likely to be an increased emphasis on managers’ technical skills

compared with traditional factory management positions, where the emphasis is on

personnel skills.