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APPENDIX B
CIM TODAY
This appendix provides supplementary information on what has been
accomplished in computer-integrated manufacturing and the directions
it can be expected to take.
SHOP FLOOR INTEGRATION TODAY
Integration across the CAD/CAM interface is in a rudimentary state
today. Flexible manufacturing systems (FMS) represent the current
state of hardware integration. The most advanced of these FMS's
consist of automated machines, equipment, and work- and tool-transport
apparatus, all operating under computer control with minimal manual
intervention. They contain all the production equipment and
production process modules of the CIM system represented in Figure 1
of Chapter 1, as well as production control software and even a
modicum of production planning software. Experience with FMS provides
some actual performance data on the benefits of integrating part of
the total system of manufacturing.
An example will illustrate the striking benefits achieved. A
flexible manufacturing system, described by Dronsek,1 has been
operating for several years at Messerschmitt-Boelkow-Blohm (MBB) in
Augsburg, West Germany. The basic elements of this system are:
(1) 25 numerically controlled (NC) machining centers and multispindle
gantry and traveling-column machines, (2) fully automated systems for
tool transport and tool changing, (3) an automatic guided vehicle
workpiece-transfer system, and (4) integrated hierarchical computer
control of all these elements.
The automatic workpiece-transfer system brings workplaces to and
from each machine tool, for operator setup, by means of computer-
controlled carts. The automatic tool-transport-and-tool-changing
system brings tools to each machine via an overhead transport system.
It then transfers the tools to a continuous elevator tool-e forage
system, which in turn provides them to the automatic tool-changing
mechanism of the machine tool. All three of these subsystems--the
machine tools, the workpiece-transfer system, and the tool-transfer
system--are coordinated, controlled, and automated by a hierarchical
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so
distributed computer system. The system is controlled by computer
numerical control (CNC) and operated by direct numerical control (DNC).
Recently MBB compared the performance of this integrated system
with the projected performance of unintegrated (stand-alone) NC
machine tools doing the same type and quantity of work. The
integration had reduced the number of NC machines required by 52.6
percent, personnel required by 52.6 percent, floor space required by
42 percent, part throughput time by 25 percent, total production time
by 52.6 percent, tooling cost by 30 percent, total annual costs by 24
percent, and capital investment costs (including all the additional
supporting and peripheral equipment and software required to
accomplish full integration) by 10 percent. This last fact alone
illustrates that CIM can free large amounts of the idle capital
associated with machines that are normally underutilized. -
MBB also has experienced nonquantifiable benefits as a result of
this level of integration. Improvement in product quality has been
realized in the form of higher accuracy and reproducibility, lower
rework costs, and lower scrap rates. This quality improvement in turn
has resulted in lower quality-assurance costs. Production schedules
are more predictable, and the typical level of paper flow has
decreased. Furthermore, working conditions have improved owing to the
decreased risk of accidents, the relief from heavy physical labor, and
the more challenging nature of the work. Finally, and most
importantly, increased flexibility has made the manufacturing
operation essentially independent of batch size, of the types of
parts, and of production quantities: sets of parts can more easily be
produced just in time for assembly, thus reducing the inventory of
parts in process.
The FMS, as an element of the computer-integrated factory of the
future, demonstrates that automation can be essentially free if
properly designed and utilized. First, a much smaller number of
automated workstations is required because of higher utilization.
capital saving more than pays for the additional integrating
facilities, including software. Secondly, the ability of these
systems to produce parts as required for immediate assembly reduces
work-in-process inventory, freeing capital and reducing interest
costs. The just-in-time production made possible by flexible
automation allows a plant to turn its total inventory more times per
year than is normal in a conventional factory.
None of these advantages, however, may be realized in the absence
of another set of factors: the foresight, courage, and commitment on
the part of management to recognize the opportunity, to accept the
risks of a new production method, and to stick with the planned course
of action until the goal is achieved.
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BENEFITS OF SELECTED APPLICATIONS
One large conglomerated made a special study of the results
achieved by a diverse group of independent companies through the
modernization of production management systems. Production management
systems are narrower than integrated CAD/CAM, but the data indicate
that significant savings have already resulted from the application of
this portion of CIM technology.
Product/
Industry Application Result
Manufacturer of
Components for
Computer
Peripherals3
Manufacturer of
Machine Tools4
Material
Requirements
Planning
Material
Requirements
Planning
Manufacturer of Material
Industrial Requirements
Maintenance Planning
Equipments
Manufacturer of Material o
Attachments for Requirements
Caterpillar Planning o
Equipment6
o 25% Reduction in Production Time
o 50% Reduction in Work in Process
Inventory
o 30% Reduction in Parts Inventory
Value
o On-Time Shipments went from 77%
to 93%
o On-Time Production Schedule
Completion from 85% (Measured
Monthly ~ to 100% (Measured Wkly
o Productivity from 62% to 68%
o Manufacturing Pas t Due Hours
from 11,000 to 1,900
0 Overtime from 4,000 Hours to
600 Hours
o Improved Inventory Accuracy
from 45% to 95%
0 Reduced Part Shortages from
300/wk to 5/wk
o Has not missed a Quarterly
Production Goal for Last Three
Years - Used to Meet Monthly
Goals 1/3 of the Time
Inventory Accuracy from 43%
to 99%
Bill of Material Accuracy
from 50% to 99%
0 Master Schedule Performance
from 63% to 95%
0 Delivery Performance from
55: to 95%
0 Shortages/Week from 150 to 0
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Product/
Industry
Application
Result
Manufacturer
of Aircraft
Electrical
Equipment7
Machine Tool
Manufacturers
Kitchen
Equipment
Manufacturers
Electronics
Computer
Manufacturers
75 Businesses
Internal to one
Conglomerate9
Material
Requirements
Planning
Manufacturing
Resource
Planning
(MRP II)
Master
Scheduling
Manufacturing
Resource
Planning
(MRP II)
Factory Data
Collection/
Production
Scheduling &
Control
Production
Control
Systems
o Consumer Products
o Light Industrial Products
o Heavy Industrial Products
o High Technology Products
o Reduced Inventory Levels
o Doubled Inventory Turns
0 Increased Orders Delivered on
Time
o Reduced Obsolete Material by 80%
o Inventory Reduced - 29%
o Inventory Accuracy Improved
from 30% to 98%
o Promises Kept Improved from
less than 10% to 60%
o Schedule Performance - 97%
o Customer Service up from
89: to 96%
0 Finished Goods Inventory
Reduced 13%
0 Work in Process Reduced 50%
o Manufacturing Cycles Reduced 50%
o Inventory Accuracy Improved
from 68% to 90%
Note: CEO uses System to run
Business
0 Labor Reduced 38%
o Output Doubled
0 Inventory Turns went from
2.5 to 6.0
0 Inventory Accuracy Better
than 98%
o Work in Process Reduced by 6%
0 80% Increase in Customer
Service Levels
o Output Cycle Time Reduced
from 35 to 12 days
0 20-25% Inventory Reduction
0 $80-90 Million Productivity
Improvement
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WHAT LEVEL OF CIM WILL BE ACHIEVED?
A recent survey of the ultimate technological potential of CIM for
improvement of manufacturing performance was done by a team of eight
of the world's leading manufacturing research experts, from five
different countries. The International Institution for Production
Engineering Research (CIRP)10 asked these experts to estimate, for
the metalworking manufacturing industry, the ultimate potential
relative to the state of the art today. The range and average of
their estimates are shown in the following table. It can be seen that
they expect large improvements in manufacturing performance. While
the range of estimates is large and the number is small, the averages
provide a not unreasonable projection.
Forecast of Ultimate Technological Potential of CIM
ABBREVIATED QUESTIONS
ESTIMATES OF RESPONDEES
RANGE AVERAGE
What do you estimate to be the ultimate
percentage change, compared to today,
that computer-based automation,
optimization, and integration in the
metalworking manufacturing industry
can achieve in the following:
Increase in manufacturing productivity? 20-200% 120%
Increase in product quality?
Decrease in lead time from design of
product to initial production for sale?
Decrease in lead time from receipt of
order to shipment?
Increase in utilization of capital
equipment?
Decrease in inventory of work in
progress?
60-200% 140Z
30-100% 60%
30-50% 45%
20-1500% 340%
30-100% 75%
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NOTES
1. M. Dronsek, "Technische und Wirtechaftliche Probleme der Pertigung
im Flugzeugbau." Proceedings, Produktionatechnisches Kolloquium
Berlin 1977
(Munich: Carl Hanser Verlag, 1979) pp. 107-115.
2. Richard H. Fabiano, General Electric Co ., Bridgeport, CT.
3 . "Computerized MAP Pays Off," American Machinist, June, 1979.
4. Oliver Wright, Production Management Systems Case Study by Video
Productions
5 . "The Trick of Material Requirements Planning," Business Week,
June 4, 1979.
6. David W. Buker, 1982 News Letter, David W. Buker, Inc.
7. "The Right Stuff: How Managers are Attacking Their Material
Problems With MAP," Material Handling Engineering, May, 1982.
8. Selected results from a General Electric Company study of
companies that have applied production management systems.
9. Selected results from internal General Electric Company
applications of production management systems.
10. M. Eugene Merchant, "Current status of, and potential for,
automation in the mete [working menu fac tur ing incus try . "
Annals of the CIRP (Vol. 32, No. 2, 1983), pp. 519-523.
Representative terms from entire chapter:
inventory accuracy
