AC:2.2 THE BIG PICTURE

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How Computers Can Be Used in an Automated Manufacturing System

Some Acronyms

CAD - Computer Aided/Automated Design - Design geometry, dimensions, etc.

CAE - Analysis of the design done in the CAD system for stresses, flows, etc. (often described as part of CAD)

CAM - Computer Aided/Automated Manufacturing - is the use of computers to select, setup, schedule, and drive manufacturing processes.

CAPP - Computer Aided Process Planning - is used for converting a design to a set of processes for production, machine selection, tool selection, etc.

PPC - Production Planning and Control - also known as scheduling. Up to this stage each process is dealt with separately. Here they are mixed with other products, as required by customer demand, and subject to limited availability of manufacturing resources.

Factory Control - On a minute by minute basis this will split up schedules into their required parts, and deal with mixed processes on a factory wide basis. (This is very factory specific, and is often software written for particular facilities) An example system would track car color and options on an assembly line.

Workcell Control - At this system level computers deal with coordination of a number of machines. The most common example is a PLC that runs material handling systems, as well as interlocks with NC machines.

Machine Control - Low level process control that deals with turning motors on/off, regulating speeds, etc., to perform a single process. This is often done by the manufacturers of industrial machinery.

AC:2.2.1 Acronyms

A Blessing and a curse

Acronyms make it possible to convey exact technical meaning in a quick efficient way. But, they also make it possible to confuse a subject with poorly defined terms

There are many acronyms involved with this book, such as CAPP, CIM, CAM, CAD, CAE, PPC, MRP, MRP-II, UNIX, DOS, CNC, DNC, etc.

AC:2.2.2 What is CAD/CAM?

Using computers for design and manufacturing

We computerize the easier tasks, which are tedious and mistake prone when done manually.

In CAD we design product geometries, do analysis (also called CAE), and produce final documentation.

In CAM, parts are planned for manufacturing (eg. generating NC code), and then manufactured with the aid of computers.

CAD/CAM tends to provide solutions to existing problems. For example, analysis of a part under stress is much easier to do with FEM, than by equations, or by building prototypes.

CAD/CAM systems are easy to mix with humans.

This technology is proven, and has been a success for many companies.

There is no `ONE WAY' of describing CAD/CAM. It is a collection of technologies which can be run independently, or connected. If connected they are commonly referred to as CIM

AC:2.2.3 What is the difference between CAD, CAM AND CIM

CAD/CAM involves the use of computers to make Design and Manufacturing more profitable.

Parts of CIM use CAD/CAM techniques and products to try and make the factory fully connected using computers.

The essential difference is CAD/CAM provides the tools, CIM is the philosophy which is used when organizing the computers, programs, etc. and all the information that flows between them.

Another way to think of CIM is that it allows the structure of an organization to be entered into the computers.

CIM focuses on connecting the various CAD/CAM modules.

AC:2.2.4 Examples of CAD/CAM Usage

An FMS is made out of CAD/CAM components (and can be PART of a CIM system).

The list below shows users of FMS in the U.S.A. The variety of applications illustrates that the technology may be used by any industry. The companies employing the technology show confidence in the technology.

Table 1:

Company	FMS location	Product	Main supplier
Aerospace: Engines
Avco Lycoming	Stratford, CT	Engine components	Kearney & Trecker
Pratt & Whitney	Columbus, GA	Engine components
General Electric	WIlmington, NC Lynn, MA	Engine components	Lodge & Shipley
Aerospace
Boeing	Auburn, WA	Aircraft components	Shin Nippon Koki
FMC Corporation	Brea, CA Aiken SC	Joints and Hoses components for military vehicles and rocket launch systems	Cincinnati Milacron
General Dynamics	Fort Worth, TX	Components for F-16 aircraft	Westinghouse
Lockheed Georgia	Marietta, GA	Airframe parts	White- Consolidated
Vought	Dallas, TX	Aircraft fuselage for B-1 bomber	Cincinnati Milacron
McDonnell Douglas	Torrence, CA St.Louis, MO	Aircraft components Missile bodies	Cincinnati Milacron Giddings & Lewis
Westinghouse Electrical Systems	Lima, OH	Aircraft generator components	Westinghouse
Equipment
Caterpillar	East Peoria, IL Decatur, IL	Tractor components	Cincinnati Milacron Giddings & Lewis
John Deere	Waterloo, IA	Tractor parts	Kearney & Trecker
Detroit Diesel	Detroit, MI	Piston engines	Lamb Technicon
Ford	New Holland, PA	Sheet metal parts for farm equipment	Trumpf
Ingersoll Rand	Roanoke, VA	Hoist equipment	White-Sunstrand
Mack-Truck	Hagerstown, MD	Transmission Housing and casting	kearney & Trecker
Machine Tool
Cincinnati Milacron	Mt. Orab, OH	Parts for plastics Processing equipment	Cincinnati Milacron
Mazak	Florence, KY	Parts for machine tools	Mazak
White- Sunstrand	Belvidere, IL	Machine tool parts	White- Consolidated
Other Industries
Allen-Bradley	Milwaukee, WI	Motor starters	kearney & Trecker
Borg Warner	York, PA	Compressor components	Comau
Federal Mogul	Littiz, PA	Bearings
G.E. Medical Systems	Milwakee, WI	Parts for medical equipments	Trumpf
Mercury Marine	Fond Du Lac, WI	Outboard motor crankcase and block	Kearney & Trecker
NY Air Base	Watertown, NY	Brake Systems
OMC-Evinrude	Milwakee, WI	Outboard motor parts	Swedish Machine Group
Onan	MInneapolis, MN	Electrical switchgear for generators	Trumpf
Remington Arms	Ilion, NY	Firearm parts
Union Special	Huntley, IL	Sewing machine bodies	kearney & Trecker
Westinghouse Electric Corp.	Pittsburgh, PA	Wire harness for electrical equipment
Xerox	Webster, NY	Panels for copiers

[Source -- find]

The table below indicates the countries which are using the FMS technology. The countries with the higher numbers of FMS systems are also a sample of the major economic leaders. [Ayres et al, 1991, pg. 212, an estimate based on limited information]

Table 2:

Country	FMS installed	percentages
Austria	6	0.7
Belgium	6	0.7
Bulgaria	15	1.7
Canada	4	0.5
CSFR	23	2.6
Finland	12	1.4
France	72	8.2
FRG	85	9.7
GDR	30	3.4
Hungary	7	0.8
India	1	0.1
Ireland	1	0.1
Israel	2	0.2
Italy	40	4.5
Japan	213	24.2
Netherlands	8	0.9
Norway	1	0.1
Poland	5	0.6
Romania	1	0.1
Singapore	1	0.1
South Korea	4	0.5
Spain	2	0.2
Sweden	37	4.2
Switzerland	6	0.7
Taiwan	5	0.6
UK	97	11.0
USA	139	15.8
USSR	56	6.4
Yugoslavia	1	0.1

[ source - find]

Driving forces of CIM/FMS are shown in the figure below

[ source - find]

AC:2.2.5 Computer Integrated Manufacturing (CIM),

We should aspire to meet the ideals of CIM when designing CAD/CAM technology

CIM architectures contain,

- Computing Hardware

- Application Software

- Database Software

- Network Hardware

- Automated Machinery

CIM benefits,

- Optimizes data flow in company

- Simplifies sharing and translation of information

- Reduces careless errors in data

- Allows checking of data against standards

- Promotes use of standards

CIM modules,

- Customer Order Entry

- Computer Aided Design (CAD) / Computer Aided Engineering (CAE)

- Computer Aided Process Planning (CAPP)

- Materials (e.g., MRP-II)

- Production Planning and Control (Scheduling)

- Shop Floor Control (e.g., FMS)

Reference model for enterprise related CIM

[find source]