© 2008 Pearson Education South Asia Pte Ltd Chapter 15: Computer-Integrated Manufacturing Systems Manufacturing Processes for Engineering Materials Manufacturing

© 2008 Pearson Education South Asia Pte Ltd© 2008 Pearson Education South Asia Pte Ltd

Chapter 15: Computer-Integrated Manufacturing SystemsChapter 15: Computer-Integrated Manufacturing SystemsManufacturing Processes for Engineering Materials Manufacturing Processes for Engineering Materials

Manufacturing Processes Manufacturing Processes for Engineering Materials for Engineering Materials

(5(5thth Edition in SI Units) Edition in SI Units)Chapter 15: Chapter 15:

Computer-Integrated Manufacturing SystemsComputer-Integrated Manufacturing Systems



Computer-Integrated Manufacturing

• Computer-integrated manufacturing (CIM) describes the computerized integration of product design, planning, production, distribution and management.

• CIM depends on usage of a large-scale integrated communications system.

• Requires extensive database containing technical and business information.




• CIM systems consists of subsystems that are integrated as a whole, such as:

1. Business planning and support2. Product design3. Manufacturing process planning4. Process automation and control5. Factory-floor monitoring systems




Benefits1. Shorter product life cycles2. Product quality and uniformity3. Better use of resources4. Better control of the processes




Some examples:1. Computer aided design and manufacturing (CAD/CAM)2. Computer numerical control (CNC)3. Adaptive control (AC)4. Industrial robots for assembly5. Automatic control6. Computer-aided process planning (CAPP)7. Group technology (GT)8. Just-in-time production (JIT)



Computer-Aided Design and Engineering

• Computer-aided design (CAD) uses the computers to create design drawings and geometric models of products and components.



Elements of computer-aided design systems

• CAD system consists of four stages:1. Geometric modeling• Constructs geometric mode with lines and dimensions.




2. Design analysis and optimization• Design is subjected to an engineering analysis.

3. Design review and evaluation• Review and evaluation to check for any interference

among various components.




4. Documentation• Detailed, working drawings are developed and printed.



Computer-Aided Manufacturing

• CAM involves the use of computer technology to assist in all phases of manufacturing.

• CAD/CAM systems allows information transfer from design to planning stage.

• Advantages of CAD/CAM are:1. standardizing product development2. reducing the effort of designing, evaluation and

prototype work



Computer-Aided Process Planning

• Process planning involves selecting methods of the sequence of operations, processing time and methods of assembly.

• Computer-aided process planning (CAPP) view total operation as an integrated system, so that individual operations are coordinated with each other.



Elements of computer-aided process-planning systems

• 2 types of CAPP systems:1. Variant System• Computer files contain a standard process plan for a

particular part to be manufactured.

2. Generative System• Process plan is automatically generated on the basis of

the same logical procedures.



Elements of computer-aided process-planning systems

Advantages of CAPP systems1. Standardization of process plans improves the

productivity.2. Process plans can be prepared.3. Process plans can be modified.4. Routing sheets can be prepared.5. Other functions can be incorporated.



Computer Simulation of Manufacturing Processes and Systems

• Process simulation takes 2 forms:1. Optimizes or improves performance.2. Analyses multiple processes and their interactions.

• Simulation helps engineers to organize and to identify critical machinery.



Computer Simulation of Manufacturing Processes and Systems

• Process simulation takes 2 forms:1. Optimize or improve performance.2. Analyse multiple processes and their interactions.

• Simulation helps engineers to organize and to identify critical machinery.

• Able to conduct ergonomic analysis of various operations and machinery setups.



Group Technology

• Group Technology (GT) is a concept to take advantage of design and processing similarities among the parts that are to be produced.

• Attractive to consumer demand for variety of products which requires batch production.



Cellular Manufacturing

• Group technology consists of one or more manufacturing cells.

• Manufacturing cell is a small unit consisting of one or more workstations.

• Cellular manufacturing used in material removal, sheet-metal forming operations and polymer processing.



Flexible Manufacturing Systems

• In FMS all elements of manufacturing are integrated into an automated system.

• Different computer instructions can be downloaded for each successive part that passes through a workstation.

• Can handle a variety of part configurations and produce in any order.



Flexible Manufacturing Systems

Elements of FMS1. Workstations2. Automated handling and transport of materials and

parts3. Control systems• System capable of transporting raw materials, blanks,

and parts in various stages of completion anytime.



Just-in-Time Production

• JIT concept has the following goals:1. Receive supplies just in time to be used.2. Produce parts just in time to be made into

subassemblies.3. Produce subassemblies just in time to be assembled

into finished products.4. Produce and deliver finished products just in time to be

sold.



Just-in-Time Production• This approach emphasizes: 1. Worker pride and dedication 2. Elimination of idle resources3. Teamwork• Advantages of JIT:1. Low inventory-carrying costs2. Rapid detection of defects3. Reduced need for inspection and reworking of parts4. Production of high-quality parts at lower cost



Lean Manufacturing

• A systematic approach to identifying and eliminating waste in every area of manufacturing.

• Helps identify whether the activity:1. adds value2. adds no value but cannot be avoided 3. adds no value but can be avoided



Artificial Intelligence• AI concerned with systems that exhibit some characteristics

are usually associated with intelligence in human behaviour.• Has impact on the design, automation and overall economics

of manufacturing operations.• AI encompasses the following:1. Expert systems.2. Natural language.3. Machine (computer) vision.4. Artificial neural networks.5. Fuzzy logic.

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© 2008 Pearson Education South Asia Pte Ltd Chapter 15: Computer-Integrated Manufacturing Systems Manufacturing Processes for Engineering Materials Manufacturing