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ComputerComputer--aided production planningaided production planning
& control& controlThe scope of production planning andThe scope of production planning and
control within a company is to plancontrol within a company is to planmanufacturing process formanufacturing process for controlcontrol
vv the flow of materialsthe flow of materials
vv toolstools
vv work in production (WIP)work in production (WIP)
ComputerComputer--aided production planningaided production planning& control& control
ComputerComputer--aided production planning &aided production planning &controlcontrol (CAPP&C)(CAPP&C) systems rely on thesystems rely on thedata generated by all other areas ofdata generated by all other areas ofCAE.CAE.
CAPP&C can be seen as being dominant inCAPP&C can be seen as being dominant inthe structure of a CIM environment.the structure of a CIM environment.
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Production PlanningProduction Planning
It involves a number of activities relatedIt involves a number of activities relatedtoto
the preperation of the manufacturingthe preperation of the manufacturing
the modification of the manufacturingthe modification of the manufacturing
the master production schedulethe master production schedule
Production PlanningProduction Planning
It includes a number of activities such asIt includes a number of activities such as
vv selecting the most appropriateselecting the most appropriateprocessprocess
vv process planningprocess planning
vv factory layoutfactory layout
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Production PlanningProduction Planning
Work Orders/Information Retrieval:Work Orders/Information Retrieval: TheThedaily planning was transformed into dailydaily planning was transformed into dailywork orders. This order included thework orders. This order included theresponsible foremen, the location of theresponsible foremen, the location of thework to be realized, the crew leader ,work to be realized, the crew leader ,the equipment required, the volume ofthe equipment required, the volume of
work and, the time at which the workwork and, the time at which the workshall be started an finished.shall be started an finished.
Production PlanningProduction Planning
Productivitymeasurement
PW,CW,NCW
Optimum crews
Optimum procedure
Productivity
Velocity
Feedback
Initial planning
Weekly planning
Productiviy
Improvement
Team
Daily planning
Field engineer
Summary reports
Information analysis
Production report
Management
Informationretrieval
Foreman
Work
orders
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Master Production ScheduleMaster Production Schedule
sets out an aggregate plan forsets out an aggregate plan forproduction.production.
is the statement of its expectedis the statement of its expectedproduction output overproduction output over the longthe long
termterm..
Master Production ScheduleMaster Production Schedule
is effectively the plan that the companyis effectively the plan that the companyhas developed for production, staffing,has developed for production, staffing,inventory, etc.inventory, etc.
has as input a variety of data, e.g.has as input a variety of data, e.g.((forecast demand, production costs, inventory costs,forecast demand, production costs, inventory costs,etc and as output a production plan detailing amountsetc and as output a production plan detailing amountsto be produced, staffing levels, etc for each of ato be produced, staffing levels, etc for each of a
number of time periodsnumber of time periods.).)
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Master Production ScheduleMaster Production Schedule
This is the most general of the options allowed by theThis is the most general of the options allowed by thepackage. LP stands forpackage. LP stands for linear programminglinear programming and is aand is ageneralised way of modelling decision problems.generalised way of modelling decision problems.
Process planningProcess planning
Planning the processes for a particularPlanning the processes for a particularcomponent / assembly is vital to the costcomponent / assembly is vital to the cost--effectiveness of a product in theeffectiveness of a product in the
marketplace.marketplace.Manual process planning involves generating aManual process planning involves generating a
set of instructions to the manufacturingset of instructions to the manufacturingplant for the production of a component / anplant for the production of a component / aneffective order for assembly.effective order for assembly.
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Process planningProcess planning
ComputerComputer--aided process planning tools fullyaided process planning tools fullyutilize the computers data storage andutilize the computers data storage andretrieval capabilities to manage a databaseretrieval capabilities to manage a databaseof this information.of this information.
More complex CAPP packages are known asMore complex CAPP packages are known asgenerative type systems.generative type systems.
SchedulingScheduling
An important aspect of planning the effecientAn important aspect of planning the effecientmanufacture of components and productsmanufacture of components and productswithin the factory is that they arewithin the factory is that they are
scheduled.scheduled.vv Shortest processing time (SPT)Shortest processing time (SPT)
vv Earliest due data (EDD)Earliest due data (EDD)
vv Moores algorithmMoores algorithm
vv Johnsons algorithmJohnsons algorithm
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Production ControlProduction Control
Production control does not only have to ensureProduction control does not only have to ensurethe correct implementation of productionthe correct implementation of productionplanning but must also provide the means toplanning but must also provide the means todynamically change the planning to suit suchdynamically change the planning to suit suchfluctuations.fluctuations.
In a computerIn a computer--aided system, the correct andaided system, the correct andtimely delivery of materials can be carriedtimely delivery of materials can be carried
out by automated materials handling devices.out by automated materials handling devices.
Materials Requirements PlanningMaterials Requirements Planning
It is a more a statement of how theIt is a more a statement of how thecompany wishes or even needs to affectcompany wishes or even needs to affectthe market rather than how the marketthe market rather than how the marketis actually performed.is actually performed.
The master production schedule is set upThe master production schedule is set upby the materials requirements planningby the materials requirements planning(MRP) system.(MRP) system.
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Materials Requirements PlanningMaterials Requirements PlanningMaterials requirements planning, referredMaterials requirements planning, referred
to by the initials MRP, is a techniqueto by the initials MRP, is a techniquewhich assists a company in the detailedwhich assists a company in the detailedplanning of its production.planning of its production.
MRP was developed in the 1960s in the USMRP was developed in the 1960s in the USto provide a computerized means ofto provide a computerized means of
controlling the availability of materialscontrolling the availability of materialsfor production.for production.
MRP OperationMRP Operation
The operation of a materials requirementsThe operation of a materials requirementsplanning system is key to that of a CIMplanning system is key to that of a CIMsystem as it utilitize data from a widesystem as it utilitize data from a widerange of the CAE facilities within arange of the CAE facilities within acompany.company.
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Materials Requirements PlanningMaterials Requirements PlanningConceptually therefore two related decisionsConceptually therefore two related decisions
about ordering are :about ordering are :
timingtiming -- when to orderwhen to order
quantityquantity -- how much to orderhow much to order
With respect to the timing decisionWith respect to the timing decision as late asas late aspossiblepossible, but never planned a stockout. This is, but never planned a stockout. This isa driving principle in MRP,a driving principle in MRP,
Never order before you need to,Never order before you need to,
never plan to stockout.never plan to stockout.
Materials Requirements PlanningMaterials Requirements Planning
MRPPROCESS
Supplier
Management
Customer
InventoryPurchase order Check-status
Inventory
Received Order
Customer orderPurchaseOrder
ReceivedPurchase Order
Result MRP-process
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MRP OperationMRP OperationMediumMedium--term planning :term planning :
The actual requirements for rawThe actual requirements for rawmaterials, component manufacture andmaterials, component manufacture andboughtbought--in component acquisition canin component acquisition cantake place.take place.
MRP OperationMRP Operation
ShortShort--term planning :term planning :
Generates shopfloor scheduling on aGenerates shopfloor scheduling on a
weekweek--byby--week or even a dayweek or even a day--byby--daydaybasis, considering single batches ofbasis, considering single batches ofcomponents/assemblies.components/assemblies.
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MRP OperationMRP OperationRealReal--time control :time control :
Of the manufacturing activities takesOf the manufacturing activities takesplace. It is carried out by the machineryplace. It is carried out by the machineryand personnel on the shopfloor but theand personnel on the shopfloor but thevital link to the MRP system.vital link to the MRP system.
MRP System StructureMRP System Structure
MRP software is essentially a databaseMRP software is essentially a databasemanagement system. The database atmanagement system. The database atthe heart of an MRP system is held inthe heart of an MRP system is held intext form.text form.
The database management system forThe database management system forMRP presents the user with a series ofMRP presents the user with a series offunctions forfunctions for accessing, distributing andaccessing, distributing andmanipulating that data.manipulating that data.
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MRP overviewMRP overviewIn MRP two types of information areIn MRP two types of information are
required:required:
StructuralStructural informationinformation
TacticalTactical informationinformation
MRP overviewMRP overview
StructuralStructural information is informationinformation is informationabout the items (parts/components)about the items (parts/components)that the company uses and howthat the company uses and how
different items are related to onedifferent items are related to oneanother. It includes information foranother. It includes information foreach item such as lead time and lot (oreach item such as lead time and lot (orbatch) size rule.batch) size rule.
The key point about this information isThe key point about this information isthat it changes relatively infrequently.that it changes relatively infrequently.
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MRP overviewMRP overviewThe structural information required inThe structural information required in
MRP relates to:MRP relates to:
item information; anditem information; and
bill of materials.bill of materials.
Bill of materialsBill of materials
In order to show the makeIn order to show the make--up (in terms of theup (in terms of theparts needed for production) we have aparts needed for production) we have a Bill ofBill ofMaterials (BOM)Materials (BOM)for the endfor the end--product (namelyproduct (namely
the chair).the chair).Chair
Back (1) Legs (4)Seat (1)
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Bill of materialsBill of materialsThe BOM is bestThe BOM is best
thought of as beingthought of as beingdivided into levels,divided into levels,with the final itemwith the final item(the chair) being at(the chair) being atthe top level and thethe top level and theitems needed toitems needed to
make up a chairmake up a chairbeing at the secondbeing at the secondlevel.level.
MRP overviewMRP overview
TacticalTactical information is information aboutinformation is information aboutthe current state of the companythe current state of the company -- forforexample sales orders (real and forecast)example sales orders (real and forecast)
pending, the master productionpending, the master productionschedule, onschedule, on--hand inventory levels andhand inventory levels andpurchase orders.purchase orders.
Obviously the key point about thisObviously the key point about thisinformation is that it changesinformation is that it changesfrequently.frequently.
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MRP overviewMRP overviewThe tactical information required in MRPThe tactical information required in MRP
relates to:relates to:
outout--going inventory (sales) and plannedgoing inventory (sales) and plannedproduction (master productionproduction (master productionschedule); andschedule); and
onon--hand inventory and inhand inventory and in--comingcoming
inventory (purchases).inventory (purchases).
MRP overviewMRP overview
The screen below is the initial screen toThe screen below is the initial screen toset up number of items, time units etc.set up number of items, time units etc.
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MRP overviewMRP overviewAn important point to note is that MRP isAn important point to note is that MRP is
not cost driven i.e. it does not seek tonot cost driven i.e. it does not seek tominimise cost.minimise cost.
Instead MRP is stockout drivenInstead MRP is stockout driven -- that isthat isit will always order sufficient to avoidit will always order sufficient to avoidstockouts (using the lot size rule forstockouts (using the lot size rule for
each item) and order as late as possible.each item) and order as late as possible.
MRPMRP -- SensitivitySensitivity
It is often important to conduct sensitivityIt is often important to conduct sensitivity(what(what--if) analysis in MRP. Considering theif) analysis in MRP. Considering theexample above, for instance, the only actionsexample above, for instance, the only actions
we need to takewe need to take nownowrelate to the ordersrelate to the orderssuggested for the current period.suggested for the current period.
All other actions relate to orders that we mayAll other actions relate to orders that we may(or may not) place at future points in time.(or may not) place at future points in time.
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Materials Requirements PlanningMaterials Requirements Planning
ProductsProduction
planning
Bill ofmaterials
Materialexplosion
Allocations
Raw MaterialsControl
ManagementReports
Stock TakeRoutines
Issues & Returns
Productioncontrol
OrderRecommendations
Receipts
GRNs
Suppliers
PurchaseOrdering
Purchaseorders
Manufacturing Resources PlanningManufacturing Resources Planning
MRP II is (essentially) MRP but with moreMRP II is (essentially) MRP but with moreadded. It may also includeadded. It may also include capacitycapacityrequirements planningrequirements planning(essentially try(essentially tryand automatically include capacityand automatically include capacityrestrictions in the planning process).restrictions in the planning process).
By the 1970s, the system had developedBy the 1970s, the system had developedinto manufacturing resource planninginto manufacturing resource planning(MRP II).(MRP II).
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Manufacturing Resources PlanningManufacturing Resources PlanningIn order to generate the net materialIn order to generate the net material
requirement plan, the software had torequirement plan, the software had toaccess theaccess the inventory control fileinventory control file. The. Theinventory control part of the softwareinventory control part of the softwareenables the file to be kept up.enables the file to be kept up.
The inventory of boughtThe inventory of bought--in parts isin parts is
serviced by and also providesserviced by and also providesinformation forinformation for purchasing controlpurchasing control..
Manufacturing Resources PlanningManufacturing Resources Planning
To confuse things MRP II stands forTo confuse things MRP II stands formanufacturing resources planningmanufacturing resources planning,,signifying that we are concentratingsignifying that we are concentratingupon the planning of the manufacturingupon the planning of the manufacturingresourcesresources (e.g. people, machines,(e.g. people, machines,storage)storage), rather than limiting ourselves, rather than limiting ourselvesto the planning of the materialsto the planning of the materialsrequirements.requirements.
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Enterprise Resource PlanningEnterprise Resource PlanningERP isERP is basicallybasically hugehuge databasesdatabases ofof informationinformation
coupledcoupled withwith businessbusiness rulesrules,, logiclogic andandconstraintsconstraints thatthat allowallow usersusers toto interactinteract..
TheThe scopescope ofof thesethese systemssystems encompassencompass thetheentireentire companycompany..
ExampleExample functionalityfunctionality includesincludes accountingaccounting,,productionproduction,, inventoryinventory,, andand customercustomer
managementmanagement..
Enterprise Resource PlanningEnterprise Resource Planning
ERP systems are the highest level systems in aERP systems are the highest level systems in acompany that allow a customer to enter ancompany that allow a customer to enter anorder, track that order, build the order, shiporder, track that order, build the order, ship
the order to the customer, and then receivethe order to the customer, and then receivepayment for the order.payment for the order.
Typical ERP data would include product lists,Typical ERP data would include product lists,inventory, customer lists, customer orders,inventory, customer lists, customer orders,invoices, purchase orders, etc.invoices, purchase orders, etc. Typical ERPTypical ERPrules would be "check customer credit beforerules would be "check customer credit beforesending order to MRP".sending order to MRP".
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JustJust--inin--timetime
JustJust--inin--TimeTime
JustJust--inin--time (JIT) is easy to grasp conceptually,time (JIT) is easy to grasp conceptually,everything happenseverything happensjustjust--inin--time.time.
For example consider the journey to work thisFor example consider the journey to work this
morning, We could have left my house,morning, We could have left my house,justjust--inin--timetimeto catch a bus to the train station,to catch a bus to the train station,justjust--inin--timetimeto catch the train,to catch the train,justjust--inin--timetimeto arrive atto arrive atmy office,my office,justjust--inin--timetimeto pick up my lectureto pick up my lecturenotes,notes,justjust--inin--timetimeto walk into this lectureto walk into this lecturetheatre to start the lecture.theatre to start the lecture.
Conceptually there is no problem about this,Conceptually there is no problem about this,however achieving it in practice is likely to behowever achieving it in practice is likely to bedifficult!difficult!
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JustJust--inin--TimeTimeSo too in a manufacturing operation componentSo too in a manufacturing operation componentparts could conceptually arrive justparts could conceptually arrive just--inin--time totime tobe picked up by a worker and used.be picked up by a worker and used.
So we would at a stroke eliminate any inventorySo we would at a stroke eliminate any inventoryof parts, they would simply arrive justof parts, they would simply arrive just--inin--time!time!Similarly we could produce finished goods justSimilarly we could produce finished goods just--inin--time to be handed to a customer who wantstime to be handed to a customer who wantsthem.them.
So, at a conceptual extreme, JIT has no need forSo, at a conceptual extreme, JIT has no need forinventory or stock, either of raw materials orinventory or stock, either of raw materials orwork in progress or finished goods.work in progress or finished goods.
JustJust--inin--Time HistoryTime History
JIT originated in Japan. Its introduction as aJIT originated in Japan. Its introduction as arecognisedrecognised technique/philosophy/way oftechnique/philosophy/way of
workingworking is generally associated with theis generally associated with theToyota motor company, JIT being initiallyToyota motor company, JIT being initiallyknown as theknown as the "Toyota Production System"Toyota Production System".".
Note the emphasis hereNote the emphasis here -- JIT is very much aJIT is very much amindset/way of looking at a production systemmindset/way of looking at a production systemthat is distinctly different from whatthat is distinctly different from what(traditionally) had been done previous to its(traditionally) had been done previous to itsconception.conception.
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Japanese View of ProductivityJapanese View of ProductivityReduce cost by eliminating wasteReduce cost by eliminating waste anyany
element of production that does not addelement of production that does not addvalue to the final productvalue to the final product
Waste is found in:Waste is found in:
vv OverproductionOverproduction
vv InventoryInventory
vv
ConveyanceConveyancevv Defects & correctionDefects & correction
vv WaitingWaiting
vv ProcessingProcessing
Just in TimeJust in Time
Produce only theProduce only the
necessary parts/necessary parts/products, in theproducts, in thenecessary quantity,necessary quantity,at the necessaryat the necessarytime.time.
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JJ--II--T ObjectivesT Objectives
Reduce cost by eliminating wasteReduce cost by eliminating waste
Make it easier to achieve & assure qualityMake it easier to achieve & assure quality
Attempt to create work sites thatAttempt to create work sites thatrespond quickly to changerespond quickly to change
Organize work sites to emphasize humanOrganize work sites to emphasize humanresourceresource
Japanese termsJapanese terms
There are a number of Japanese terms associated withThere are a number of Japanese terms associated withJIT that you may encounter. I have listed some belowJIT that you may encounter. I have listed some belowfor you:for you:AndonAndon -- trouble lights which immediately signal to thetrouble lights which immediately signal to the
production line that there is a problem to be resolvedproduction line that there is a problem to be resolvedJikodaJikoda -- autonomationautonomation -- enabling machines to beenabling machines to beautonomous and able to automatically detect defectsautonomous and able to automatically detect defectsMudaMuda -- wastewasteMuraMura -- unevennessunevennessMuriMuri -- excessexcessPokaPoka--yokeyoke -- "foolproof" machines and methods so as to"foolproof" machines and methods so as toprevent production mistakesprevent production mistakesShojinkaShojinka -- a workforce flexible enough to cope witha workforce flexible enough to cope withchanges in production and using different machineschanges in production and using different machinesSoikufuSoikufu -- thinking creatively, having inventive ideasthinking creatively, having inventive ideas
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JIT ApproachJIT ApproachIntegrated (systems)Integrated (systems)approach to productionapproach to productionEfficiently useEfficiently useresources (facilities;resources (facilities;materials; labor)materials; labor)Eliminate wasteEliminate waste(muda), uneveness(muda), uneveness(mura), and overburden(mura), and overburden(muri)(muri) 3 ms3 msInventoryInventory
The Aims of JustThe Aims of Just--inin--timetime
The principles is envisaged in Waldner refer toThe principles is envisaged in Waldner refer toas the five zeros attitude namely,as the five zeros attitude namely,
Zero stockZero stockZero lead timeZero lead time
Zero defectsZero defects
Zero breakdownsZero breakdowns
Zero paperworkZero paperwork
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JustJust--inin--timetimeJIT is a suitable production system when:JIT is a suitable production system when:have steady production of clearly definedhave steady production of clearly definedstandard productsstandard products
a reasonable number of units madea reasonable number of units made
a high value producta high value product
have flexible working practices and ahave flexible working practices and adisciplined workforcedisciplined workforce
short setup times on machinesshort setup times on machinesquality can be assured, e.g. zero defectsquality can be assured, e.g. zero defectseither though good working practices oreither though good working practices orthough a cost penaltythough a cost penalty
"Just"Just--inin--time" and its Logistictime" and its Logistic
This new notion amplifies the role ofThis new notion amplifies the role oftransport merchandise particularly intransport merchandise particularly intrucking.trucking.
It involves the delivery of a component ofIt involves the delivery of a component ofassemblage a few minutes before theassemblage a few minutes before theassembly line requires it.assembly line requires it.
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"Just"Just--inin--time" and its Logistictime" and its Logistic
Consequences: transporters must respectConsequences: transporters must respecttighter delivery schedules and must plantighter delivery schedules and must plantheir operations accordingly in order totheir operations accordingly in order to
avoid strict penalties.avoid strict penalties.The unit of production (the factory) noThe unit of production (the factory) nolonger has to assume a storage service.longer has to assume a storage service.Some analysts have pointed out that theSome analysts have pointed out that thetrucks (vehicles) themselves havetrucks (vehicles) themselves haveassumed the task of ambulatory storageassumed the task of ambulatory storageunits, thus increasing road trafficunits, thus increasing road trafficcongestion.congestion.
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JustJust--InIn--TimeTimeJustJust--InIn--Time Programming has provided withTime Programming has provided with
much needed acceleration in operations in fivemuch needed acceleration in operations in fivevital areas:vital areas:Generating toolpaths fast enough for highGenerating toolpaths fast enough for high--speed machining.speed machining.Handling lastHandling last--minute engineering changes.minute engineering changes.Training new machinists to be programmers asTraining new machinists to be programmers aswell.well.
Reduced electrical discharge machining.Reduced electrical discharge machining.Handling larger toolpath program files up toHandling larger toolpath program files up to80 MB.80 MB.
JustJust--InIn--TimeTime
The relationship between highThe relationship between high--speedspeedmachining and atmachining and at--thethe--machinemachineprogramming is crucial.programming is crucial.
HighHigh--speed machining chews throughspeed machining chews throughtoolpaths so quickly that attoolpaths so quickly that at--thethe--machine programming is almost amachine programming is almost arequirement.requirement.
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JustJust--InIn--TimeTime"In programming, we are never more than"In programming, we are never more than
half a shift or one shift ahead of thehalf a shift or one shift ahead of themachine tool,"machine tool," said Joseph Geerts,said Joseph Geerts,
"The old way of overnight batch"The old way of overnight batchprogramming for toolpaths is long gone."programming for toolpaths is long gone."
Elements of JustElements of Just--InIn--TimeTime
regular meetings of the workforce (e.g.regular meetings of the workforce (e.g.daily/weekly)daily/weekly)discuss work practices, confront and solvediscuss work practices, confront and solveproblemsproblemsan emphasis on consultation and cooperation (i.e.an emphasis on consultation and cooperation (i.e.involving the workforce) rather than confrontationinvolving the workforce) rather than confrontationmodify machinery, e.g. to reduce setup timemodify machinery, e.g. to reduce setup timereduce buffer stockreduce buffer stockexpose problems, rather than have them coveredexpose problems, rather than have them coveredupupreveal bad practicesreveal bad practicestake away the "security blanket" of stocktake away the "security blanket" of stock
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Benefits of JITBenefits of JIT
Increased productivityIncreased productivityBetter qualityBetter qualityReduced lead timeReduced lead timeLess scrap & reworkLess scrap & rework (less resources)(less resources)Less work in processLess work in process (WIP)(WIP)
Higher worker motivation & moreHigher worker motivation & moreteamworkteamwork
Benefits of JIT (contd)Benefits of JIT (contd)
Saved spaceSaved space
Increased worker & equipmentIncreased worker & equipment
efficiencyefficiencyBenefits across functional boundariesBenefits across functional boundaries(e.g., manufacturing; manufacturing(e.g., manufacturing; manufacturingengineering; purchasing; sales &engineering; purchasing; sales &marketing; accounting; quality control;marketing; accounting; quality control;assembly)assembly)
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Benefits of JITBenefits of JITFinally ,Finally ,
Easy to talk about, difficult toEasy to talk about, difficult toimplementimplementProblems solved at root cause levelProblems solved at root cause levelDoesnt allow for labor or equipmentDoesnt allow for labor or equipmentdisruptiondisruption
Doesnt consider market forecastingDoesnt consider market forecastingproceduresproceduresBenefits outweigh challengesBenefits outweigh challenges
WIPWIP
The whole stock or inventory for a JITThe whole stock or inventory for a JITcompany is in the work in progresscompany is in the work in progress(WIP).(WIP).
The principle of zero stock must also beThe principle of zero stock must also bereflected in how much of this there is.reflected in how much of this there is.
The amount of WIP can be reduced byThe amount of WIP can be reduced bythe shortening of interthe shortening of inter--operationaloperationaltransportation times.transportation times.
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JITJITValue added, Kaizen, Six sigma, Quality at theSource, Problem Solving Tools, Planning Tools
KanbanPoka YokePullVHITPMSMED5 SJidokaGroup Technologymanufacuting cell
EmpowermentManagement support
TrainingQuality circles
Work teams
Job rotationJob enlargementJob enrichment
Profit sharing
TQM
PIJIT
Manufacturing
Techniques
KanbanKanban
The Japanese worldThe Japanese world kanbankanban meansmeans cardcard ororsignsign and it is by the use of cards orand it is by the use of cards orkanbans that continuous flow ofkanbans that continuous flow ofproduction within this type of JITproduction within this type of JITsystem is regulated.system is regulated.
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KanbanKanbanIn order to have a method of controllingIn order to have a method of controlling
production (the flow of items) in this newproduction (the flow of items) in this newenvironment Toyota introduced theenvironment Toyota introduced thekanbankanban..
The kanban is essentially information as toThe kanban is essentially information as towhat has to be done. Within Toyota thewhat has to be done. Within Toyota the
most common form of kanban was amost common form of kanban was arectangular piece of paper within arectangular piece of paper within atransparent vinyl envelope.transparent vinyl envelope.
KanbanKanban
InIn ToyotaToyota twotwo typestypes ofof kanbankanban arearedistinguisheddistinguished forfor controllingcontrolling thethe flowflow ofofitemsitems::
aa withdrawalwithdrawal kanbankanban -- whichwhich detailsdetails thetheitemsitems whichwhich shouldshould bebe withdrawnwithdrawn fromfromthethe precedingpreceding step instep in thethe processprocess
aa productionproduction orderingordering kanbankanban -- whichwhichdetailsdetails thethe itemsitems toto bebe producedproduced
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Kanban TypesKanban TypesWithdrawl kanbanWithdrawl kanban
pass authorizes movement of partspass authorizes movement of partsfrom one work center to another;from one work center to another;stays with parts until partsstays with parts until partsconsumed, then returns for partconsumed, then returns for part
replenishment.replenishment.
Kanban TypesKanban Types
Production kanbanProduction kanban
release order to preceding processrelease order to preceding process
to build specified number of parts.to build specified number of parts.
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Withdrawl KanbanWithdrawl Kanban
Part Number
Container capacity(number of parts)
Raw materials and otherpart types used in
manufacturing at thework center
Preceding work center number
Stock location number
Production KanbanProduction Kanban
Part number
Container capacity(number of parts)
Number of kanbansreleased
Subsequent workcenter number
Stock locationnumber
Proceding workcenter number
Stock location number
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Rules for KanbanRules for KanbanNo withdrawal of parts without aNo withdrawal of parts without akanbankanbanSubsequent process comes to withdrawSubsequent process comes to withdrawonly what is neededonly what is neededDo not send defective parts toDo not send defective parts tosubsequent processsubsequent process
Preceding process should produce onlyPreceding process should produce onlyexact quantity of parts withdrawn byexact quantity of parts withdrawn bysubsequent processsubsequent process
Rules for Kanban (contd)Rules for Kanban (contd)
Smoothing (minimize fluctuations) ofSmoothing (minimize fluctuations) ofproductionproduction
Fine tuning of production using kanbanFine tuning of production using kanbanStop process if productionStop process if productionrequirements decreaserequirements decrease
Use overtime & improvements inUse overtime & improvements inprocesses if production requirementsprocesses if production requirementsincreaseincrease
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KanbanKanban
a signal or message or communication,a signal or message or communication,e.g. wave hands, shout, send a card,e.g. wave hands, shout, send a card,electronicelectronic
used to control the flow of itemsused to control the flow of itemsthough the production processthough the production process
Other Important ConceptsOther Important Concepts
JidokaJidoka warning system to indicatewarning system to indicateproduction problemsproduction problems (minor to serious)(minor to serious)AutonomationAutonomation manual or automaticmanual or automaticstopping of production if defective partstopping of production if defective partis producedis producedMixed productionMixed production make all models atmake all models atsame time on same linesame time on same lineWork improvementWork improvement ideas of workersideas of workersimprove productionimprove production
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Concepts (contd)Concepts (contd)
MultiMulti--work assignmentwork assignment workersworkersshifted to other jobs as neededshifted to other jobs as needed
FoolFool--proof methodsproof methods variousvarioustechniques that prevent mistechniques that prevent mis--assemblyassemblyor other defect causing actionsor other defect causing actions
Total quality controlTotal quality control no defective partno defective partis passed on to next process/operationis passed on to next process/operation
Computer aided project planning &Computer aided project planning &controlcontrol
Questions :Questions :
1.1. What is the JIT approach to quality?What is the JIT approach to quality?
2.2. Show how Kanban is used to control work flow inShow how Kanban is used to control work flow inrepetitive manufacturing environments.repetitive manufacturing environments.
3.3. How does the JIT approach to manufacturingHow does the JIT approach to manufacturingdeal with the relationship between product anddeal with the relationship between product andprocess variety?process variety?
4.4. List the five zeros aimed for in a JIT systemList the five zeros aimed for in a JIT systemand explain by what methods their achievementand explain by what methods their achievementis attempted.is attempted.
