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CAD/CAM = Computer Aided Design/ Computer Aided Manufacturing

It is the technology concerned with the use of computers to perform design and manufacturing functions

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CAD can be defined as the use of computer systems to perform certain functions in the design process

CAM is the use of computer systems to plan, manage and control the operations of manufacturing plant through either direct or indirect computer interface with the plant’s production resources

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In order to establish the scope and definition of CAD/CAM in an engineering environment and identify existing and future related tools, a study of a typical product cycle is necessary.

The following Figure shows a flowchart of such a cycle-

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The Manufacturing Process

The Design Process

Synthesis Analysis The CAD Process

The CAM Process

Design needs

Design definitions,

specifications, and requirements

Collecting relevant design information and feasibility study

Design conceptualization

Design modeling and

simulation

Design analysis

Design optimization

Design evaluation

Design documentation and

communication

Process planning

Order materials

Design and procurement of

new tools

Production planning

NC, CNC, DNC programming

ProductionQuality control

Packaging

Marketing

Shipping

Typical Product Life Cycle

The product begins with a need which is identified based on customers' and markets' demands

The product goes through two main processes from the idea conceptualization to the finished product:

The design process The manufacturing process

The main sub-processes that constitute the designprocess are:

› Synthesis› Analysis

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Definition of geometric model

Definition translator

Geometric model

Design and Analysis algorithms

Drafting anddetailing

Documentation

To CAM Process

Interface algorithms

Design changes

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Design phase Required CAD toolsDesign conceptualization Geometric modeling techniques;

Graphics aids; manipulations; and visualization

Design modeling and simulation Same as above; animation; assemblies; special modeling packages

Design analysis Analysis packages; customized programs and packages

Design optimization Customized applications; structural optimization

Design evaluation Dimensioning; tolerances; NC

Design communication and documentation

Drafting and detailing

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Geometric model

Interface algorithms

Process planning

Inspection

Assembly

Packaging

To shipping and marketing

NC programs

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Manufacturing phase Required CAM tools

Process planning CAPP techniques; cost analysis; material and tooling

specification

Part programming NC programming

Inspection CAQ; and Inspection software

Assembly Robotics, simulation and programming

CAM Tools Required to Support the Design Process

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Computer graphics concepts

Design toolsGeometric modeling

CADtools

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Design tools + Computer

Hardware(control unit; display

terminals; I/O devices

Software (graphics; modeling; applications

programs

= CAD tools

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Networking concepts

Mfg toolsCAD

CAMtools

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Definition of CAM Tools Based on Their Implementation in a Manufacturing Environment

Mfg tools + Computer

Hardware(control unit; display

terminals; I/O devices

Software (CAD; NC; MRP; CAPP)

= CAM tools

Networking

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Definitions of CAD/CAM Tools Based on Their Constituents

Mfg tools

Networking

Design tools

Geometric modeling

Computer graphics concepts

CAD/CAMtools

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Definition of CAD/CAM Tools Based on Their Implementation in an Engineering

Environment

Design andMfg tools

Hardware

Software = CAD/CAM tools

Networking

+ Computer

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LECTRA SYSTEM of FRANCE is a world famous CAD / CAM system which offers total CAD/CAM solutions for today and give you passport for tomorrow.

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Automation can be defined as the technology concerned with the application of complex mechanical, electronic, and computer-based systems in the operation and control of manufacturing systems.

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Types of Manufacturing Systems1. Continuous-flow processes. Continuous dedicated production

of large amount of bulk product. Continuous manufacturing is represented by chemicals, plastics, petroleum, and food industries.

2. Mass production of discrete products. Dedicated production of large quantities of one product (with perhaps limited model variations). Examples include automobiles, appliances and engine blocks.

3. Batch production. Production of medium lot sizes of the same product. The lot may be produced once or repeated periodically. Examples: books, clothing and certain industrial machinery.

4. Job-shop production. Production of low quantities, often one of a kind, of specialized products. The products are often customized and technologically complex. Examples: prototypes, aircraft, machine tools and other equipment.

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Production quantity

Continuous-flow

production Mass production

Batch production

Job shop production

Product variety

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Category Automation achievements

Continuous-flow process •Flow process from beginning to end•Sensors technology available to measure important process variables •Use of sophisticated control and optimization strategies•Fully computer automated lines

Mass production of discrete products

•Automated transfer machines•Dial indexing machines•Partially and fully automated assembly lines•Industrial robots for spot welding, part handling, machine loading, spray painting, etc.•Automated material handling systems•Computer production monitoring

Batch production •Numerical control (NC), direct numerical control (DNC), computer numerical control (CNC).•Adaptive control machining•Robots for arc welding, parts handling, etc.•CIM systems.

Job shop production •Numerical control, computer numerical control

Greater flexibility Reduced lead times Reduced inventories Increased Productivity Improved customer

service Improved quality Improved

communications with suppliers

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Better product design Greater

manufacturing control

Supported integration Reduced costs Increased utilization Reduction of machine

tools Less floor space

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Computer-integrated manufacturing (CIM) is the manufacturing approach of using computers to control the entire production process

This integration allows individual processes to exchange info with each other and initiate actions

Typically CIM relies on closed-loop control processes, based on real-time input from sensors

It is also known as flexible design and manufacturing

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CIM reduces the human component of manufacturing and thereby relieves the process of its slow, expensive and error-prone component

In a CIM system functional areas such as design, analysis, planning, purchasing, cost accounting, inventory control, and distribution are linked through the computer with factory floor functions such as material handling and management, providing direct control and monitoring of all the operations

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As a method of manufacturing, three components distinguish CIM from other manufacturing methodologies:

› Means for data storage, retrieval, manipulation and presentation

› Mechanisms for sensing state and modifying processes

› Algorithms for uniting the data processing component with the sensor/modification component

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Manufacturing engineers are required to achieve the following objectives to be competitive in a global context:

› Reduction in inventory› Lower the cost of the product› Reduce waste› Improve quality› Increase flexibility in manufacturing to

achieve immediate and rapid response to: Product & Production changes Process & Equipment change Change of personnel

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Integration of technologies brings following benefits:

1. Creation of a truly interactive system that enables manufacturing functions to communicate easily with other relevant functional units

2. Accurate data transferability among manufacturing plant or subcontracting facilities at implant or diverse locations

3. Faster responses to data-changes for manufacturing flexibility

4. Increased flexibility towards introduction of new products

5. Improved accuracy and quality in the manufacturing process

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6. Improved quality of the products7. Control of data-flow among various units and

maintenance of user-library for system-wide data8. Reduction of lead times which generates a

competitive advantage9. Streamlined manufacturing flow from order to

delivery10. Easier training and re-training facilities

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CIM software comprises computer programs to carry out the following functions:

› Management Information System› Sales & Marketing & Finance› Database Management› Modeling and Design› Analysis› Simulation› Communications› Monitoring› Production Control› Manufacturing Area Control

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Devices and equipment required:

› CNC, Computer numerical controlled machine tools

› DNC, Direct numerical control machine tools› PLCs, Programmable logic controllers› Robotics› Computers› Software› Controllers› Networks› Interfacing› Monitoring equipment

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Technologies

› FMS (Flexible Manufacturing System)

› ASRS (Automated Storage and Retrieval System)

› AGV (Automated Guided Vehicle)

› Robotics› Automated conveyor

systems

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The reasons why CIM is used in industries can be related to two major aspects:

1. Technical benefits 2. Financial benefits

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Data, whether quality or productivity data, is available immediately. This can help in quick decision making, thereby reducing the risks involved in continuous manufacturing.

Each product’s signature and quality traits are clearly observed and recorded, thus forming a basis in places where traceability is used

Equipment performance and similar data like downtime can be easily monitored

It is easy to correlate the performance of the product with the condition of the equipment at that particular time

Occurrence can be easily tracked to kick-start Six Sigma projects

Over 40% time reduction in data collection and aggregation activity

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Reduction in manpower of over one man per two assembly lines for fully automated lines with manual QC checking and reporting

Product data can be easily traced, thereby eliminating the cost of rework and reducing the cost of recall. Estimated recall cost reduction can be as high as 80% with some products.

Quality enhancement using CIM systems can go as far as 90% where traditional systems can reach 70% through quick correlation, thereby enhancing productivity results

Downtime can be reduced by over 80% through continuous monitoring and predictive alarms

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Kalpakjian, Serope; Schmid, Steven (2006), Manufacturing engineering and technology (5th ed.), Prentice Hall, p. 1192. 

www.en.wikipedia.org/wiki Laplante, Phillip A. (2005), Comprehensive dictionary of electrical

engineering (2nd ed.), CRC Press, p. 136.  Waldner, Jean-Baptiste (September, 1992). Principles of

Computer-Integrated Manufacturing. London: John Wiley & Sons. pp. 128-p132.

AMICE Consortium (1991). Open System Architecture for CIM, Research Report of ESPRIT Project 688, Vol. 1, Springer-Verlag, 1989.

AMICE Consortium (1991), Open System Architecture, CIMOSA, AD 1.0, Architecture Description, ESPRIT Consortium AMICE, Brussels, Belgium.

F. Vernadat (1996). Enterprise Modeling and Integration. p.40 Richard C. Dorf, Andrew Kusiak (1994). Handbook of Design,

Manufacturing, and Automation. p.1014

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