work stoppages

There are certain fundamental strategies that can be employed to improve productivity in

manufacturing operations technology. These are referred as automation strategies.

1. Specialization of operations: The first strategy involves the use of special purpose

equipment designed to perform one operation with the greatest possible efficiency. This is

analogous to the concept of labour specializations, which has been employed to improve labour

productivity.

2. Combined operations: Production occurs as a sequence of operations. Complex parts

may require dozens, or even hundreds, of processing steps. The strategy of combined operations

involves reducing the number of distinct production machines or workstations through which the

part must be routed. This is accomplished by performing more than one operation at a given

machine, thereby reducing the number of separate machines needed. Since each machine typically

involves a setup, setup time can be saved as a consequence of this strategy. Material handling

effort and nonoperation time are also reduced.

3. Simultaneous operations: A logical extension of the combined operations strategy is to

perform at the same time the operations that are combined at one workstation. In effect, two

or more processing (or assembly) operations are being performed simultaneously on the same

workpart, thus reducing total processing time.

4. Integration of operations: Another strategy is to link several workstations into a single

integrated mechanism using automated work handling devices to transfer parts between stations.

In effect, this reduces the number of separate machines though which the product must be

scheduled. With more than one workstation, several parts can be processed simultaneously,

thereby increasing the overall output of the system.

5. Increased flexibility: This strategy attempts to achieve maximum utilisation of equipment

for job shop and medium volume situations by using the same equipment for a variety of products.

It involves the use of the flexible automation concepts. Prime objectives are to reduce setup time

and programming time for the production machine. This normally translates into lower manufacturing

lead time and lower work-in-

n-productive time exists in the use of automated material handling and storage systems. Typical

benefits included reduced work-in-process and shorter manufacturing lead times.

7. On-line inspection: Inspection for quality of work is traditionally performed after the

process. This means that any poor quality product has already been produced by the time it is

inspected. Incorporating inspection into the manufacturing process permits corrections to the

process as product is being made. This reduces scrap and brings the overall quality of product

closer to the nominal specifications intended by the designer.

8. Process control and optimization: This includes a wide range of control schemes

intended to operate the individual process and associated equipment more efficiency. By this

strategy, the individual process times can be reduced and product quality improved.

9. Plant operations control: Whereas the previous strategy was concerned with the

control of the individual manufacturing process, this strategy is concerned with control at the plant

level of computer networking within the factory.

10. Computer integrated manufacturing (CIM): Taking the previous strategy one step

further, the integration of factory operations with engineering design and many of the other

business functions of the firm. CIM involves extensive use of computer applications, computer

data bases, and computer networking in the company

The objectives of the use of flow line automation are:

1. To reduce labour costs;

2. To increase production rates;

3. To reduce work-in-process;

4. To minimize distances moved between operations;

5. To achieve specialization of operations; and

6. To achieve integration of operations.

There are two general forms that the workflow can take. These two configurations are inline and rotary.

In-line Type

The in-line configuration consists of a sequence of workstations in a more-or-less straight line

arrangement. The flow of work can take a few 90° turns, either for workpiece reorientation,

factory layout limitations, or other reasons, and still qualify as a straight-line configuration. A

common pattern of workflow, for example, is a rectangular shape, which would allow the same

operator to load the starting workpiece and unload the finished workpiece.

Rotary Type

In the rotary configuration, the workparts are indexed around a circular table or dial. The

workstations are stationary and usually located around the outside periphery of the dial. The parts

ride on the rotating table and are registered or positioned, in turn, at each station for its processing

or assembly operation. This type of equipment is often referred to as an indexing machine or dial

index machine and the configurations.

The choice between the two types of configurations depends on the application. The rotary

type is commonly limited to smaller workpieces and to fewer stations. There is no flexibility in

the design of the rotary configuration. The rotary configuration usually involves a lower-cost

piece of equipment and typically requires less factory floor space. The in-line design is preferable

for larger work pieces and can accommodate a larger number of workstations. In-line machines

can be fabricated with a built-in storage capability to smooth out the effect of work stoppages

at individual stations and other irregularities.