Brief introduction to CAD and CAM – Manufacturing planning, Manufacturing control- Introduction to CAD/CAM – Concurrent engineering

PPT

1. ME6703 -COMPUTER INTEGRATED
MANUFACTURING SYSTEMS
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2. © J.Jeevamalar, EGSPEC

3. UNIT I –Introduction (10)
BriefintroductiontoCADandCAM
ManufacturingPlanning,Manufacturingcontrol
IntroductiontoCAD/CAM
ConcurrentEngineering-CIMconcepts
ComputerizedelementsofCIMsystem
Typesofproduction
ManufacturingmodelsandMetrics
MathematicalmodelsofProductionPerformance–SimpleProblems
ManufacturingControl–SimpleProblems
BasicElementsofanAutomatedsystem
LevelsofAutomation
LeanProduction
Just-In-TimeProduction.
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4. Product Development Cycle
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5. Sequential Vs
Concurrent Engineering
Vs
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6. Implementation of Concurrent
Engineering
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7. Computer-Aided Techniques
CAD (Computer-Aided Design)
CAE (Computer-Aided Engineering)
CAPP (Computer-Aided Process Planning)
PPC (Production Planning and Control)
ERP (Enterprise Resource Planning)
CAM (Computer-Aided Manufacturing)
CAQ (Computer-Aided Quality Assurance)
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8. Interface between CAD/CAM
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9. Computer Integrated Manufacturing
ComputerIntegratedManufacturing(CIM)isthe
manufacturingapproachofusingcomputerstocontrolthe
entireproductionprocess.
InaCIMsystemfunctionalareassuchasDesign,
Analysis,Planning,Purchasing,CostAccounting,
InventoryControlandDistributionarelinkedthroughthe
ComputerwithfactoryfloorfunctionssuchasMaterials
HandlingandManagement,providingDirectControl
andMonitoringofalltheoperations.
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10. CIM Wheel
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11. Computerized Elements of CIM
System
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12. Elements of CIM
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13. Activities of CIM
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14. Benefits of CIM
•Manufacturingengineersarerequiredtoachievethe
followingobjectivestobecompetitiveinaglobalcontext,
–Reductionininventory
–Lowerthecostoftheproduct
–Reducewaste
–Improvequality
–Increaseflexibilityinmanufacturingtoachieve
immediateandrapidresponseto:
•Product&Productionchanges
•Process&Equipmentchange
•Changeofpersonnel
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15. ApplicationofPhysicalandChemicalprocessesto
alterthegeometry,properties,and/orappearanceof
agivenstartingmaterialtomakepartsorproducts.
Overview of Manufacturing
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16. Manufacturing Defined -
Economic Definition
Transformationofmaterialsintoitemsofgreatervalue
bymeansofoneormoreProcessingand/or
Assemblyoperations
Manufacturing addsvalueto the material
Examples:
Converting iron ore to steel adds value
Transforming sand into glass adds value
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17. Manufacturing Defined -
Economic Definition
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18. Production Quantity
Number of units of a given part or product produced
annually by the plant
Three quantity ranges:
1.Low production –1 to 100 units
2.Medium production –100 to 10,000 units
3.High production –10,000 to millions of units
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19. Production
Systems
Batch
Production
Continuous
Production
Mass Production
Flow
Production
Job Shop
Production
Production Types
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20. Types of Production Facility
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21. Variety of metrics used by successful manufacturing to
help managing company’s operations
Quantitative metrics used to:
Track performance in successive periods (i.e. months
& years)
Try out new technologies & new systems to determine
company’s merits
Identify problems with performance
Compare alternative methods
Make good decisions
Manufacturing Models and Metrics
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22. Manufacturing Models and Metrics
 Manufacturing Metrics can be divided into 2 basic
categories:
1) Production performance measure
2) Manufacturing Costs
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23. Production concepts and
Mathematical Models
Metrics that indicates Production Performance:
Production Rate (Rp)
Production Capacity (PC)
Utilization (U)
Availability (A)
Manufacturing Lead Time (MLT)
Work-In-Progress (WIP)
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24. Metrics that indicates Manufacturing Costs:
Labor & material costs
Costs of producing products
Cost of operating a given piece of equipment
Production concepts and
Mathematical Models
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25. Operation Cycle Time
Typical cycle time for a production operation:
Tc = To + Th + Tth
where Tc = Cycle Time,
To = Processing Time for the Operation
Th = Material Handling Time (e.g., loading and unloading
the production machine)
Tth = Tool Handling Time (e.g., time to change tools)
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26. Production Rate (Rp)
Inmanufacturing,thenumberofgoodsthatcanbeproducedduring
agivenperiodoftime.Alternatively,theamountoftimeittakesto
produceoneunitofagood.
Formanufacturingandconstruction,ahigherproductionratecanlead
toadecreaseinquality.
Usuallyexpressedinhourlyrate
Consider3typesofproduction–JobShop,BatchProd&Mass
Productions
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27. In Batch Production, time to process one batch of Q work
units is
Batch time, Tb= Tsu+ QTc
where;
Tb = batch processing time (min)
Tsu = setup time to prepare for the batch (min)
Q = batch quantity (pc)
Tc = operation cycle time per work unit (min/cycle)
Assuming one work unit is completed each cycle, thus Tc
also has units of min/pc
Production Rate (Rp) –Batch Prod.
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28. By dividing batch time with batch qty:
Average production time per work unit for the given
machine, Tp = Tb /Q
Production rate, Rp = 1/Tp
The average production rate for the machine, Rp = 60/Tp
Rp = hourly production rate (pc/hr)
Tp = average production time per work unit (min/pc)
60 = constant to convert minutes to hours
Production Rate (Rp) –Batch Prod.
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29. In Job Shop Production, when Q =1;
The production time per work unit, Tp is:
Tp = Tsu + Tc
Tsu = Setup time to prepare for the batch (min)
Tc = Operation cycle time per work unit (min/cycle)
If Q > 1, revert to batch production case
Production Rate (Rp) –Job Shop Prod.
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30. The machine production rate is determined by taking the
reciprocal of Tc,
Rc= 60 / Tc
Where,
Rc = theoretical or ideal production rate / cycle rate
(cycles/hr)
Tc = ideal cycle time (min/cycle)
60 = constant to convert minutes to hours
Production Rate (Rp) –Mass Prod.
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31. Production Capacity
ProductionCapacitydefinedas:themaximumrateofoutput
thataproductionfacilityisabletoproduceunderagivensetof
assumedoperatingconditions
PC = n SwHs Rp
Where,
PC=weeklyproductioncapacityofthefacility(outputunits/wk)
n=no.ofworkcentersworkinginparallelproducinginthe
facility
Sw=no.ofshiftsperperiod(shift/wk)
Hs=hr/shift(hr)Rp=hourlyproductionrateofeachworkcenter
(outputunits/hr)
Workcentermanufacturingsystemintheplanttypically
consistingofoneworker&onemachine
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32. Utilization
Utilization=amountofoutputofaproductionfacilityrelativeto
itscapacity
U=Q/PC
U=utilizationofthefacility
Q=actualqtyproducedbythefacilityduringagiventimeperiod(i.e.
pc/wk)
PC=productioncapacityforthesameperiod(i.e.pc/wk)
Utilizationcanbeassessedfortheentireplant/anyother
productiveresources(i.e.labor)
Itisoftendefinedastheproportionoftimethatthefacilityis
operatingrelativetothetimeavailable
Usuallyexpressedin%
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33. Availability = a common measure of reliability for equipment
Especially appropriate for automated production equipment:
A = MTBF / MTBF -MTTR
A= availability (typically in %)
MTBF = mean time between failures (hr)
MTTR = mean time to repair (hr)
MTBF indicates the average length of time between breakdowns of
equipment
MTTR indicates the average time required to service the equipment &
put back into operation when breakdown occurs
Availability
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34. Manufacturing Lead time (BATCH)
ManufacturingLeadTime,MLT=totaltimerequiredto
processagivenpartorproductthroughtheplant
Simplifiedform:
MLT=averageManufacturingLeadTimeforapart/product(min)
no=no.ofseparateoperations(machines)
Tsu=setuptimeforoperation
Q=qtyofpart/product
Tc=operationcycletime
Tno=non-operationtime
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35. Work-In-Process
WIP=work-in-processinthefacility(pc)
A=availability
U=utilization
PC=productioncapacityofthefacility(pc/wk)
MLT=manufacturingleadtime(hr)
Sw=no.ofshiftsperweek(shift/wk)
Hsh=hourspershift(hr/shift)
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36. Costs of Manufacturing Operations
Fixed costs -remain constant for any output level
Variable costs -vary in proportion to production
output level
Adding fixed and variable costs
TC = FC + VC(Q)
where
TC= total costs
FC= fixed costs (e.g., building, equipment, taxes)
VC= variable costs (e.g., labor, materials, utilities)
Q= output level
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37. Fixed and Variable Costs
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38. Manufacturing Costs
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39. Basic Elements of an Automated
System
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