Date post: | 27-Jun-2015 |
Category: |
Documents |
Upload: | aghataimor |
View: | 81 times |
Download: | 3 times |
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Chapter 11Chapter 11
Just-In-Time and Just-In-Time and Lean ProductionLean Production
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
JIT: Definitions? JIT: Definitions?
• JIT Head
• Chicken JIT
• Oh JIT (O´JIT)
• Tough JIT
• Strate JITs
• JIT Planes • Bull JIT • Le JIT • JIT Lag • When the JIT hits
the fan.
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Producing only what is needed, Producing only what is needed, when it is neededwhen it is needed
A philosophy A philosophy An integrated management systemAn integrated management systemJIT’s mandate: JIT’s mandate:
Eliminate all wasteEliminate all waste
What is JIT ?What is JIT ?
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
What is JIT?What is JIT?• a corporate system designed to produce
output within the minimum lead time and at the lowest total cost by continuously identifying and eliminating all forms of corporate waste and variance.
• a corporate strategy • a philosophy • Focus of JIT:
• variance & waste
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Seven Basic Types of Seven Basic Types of WasteWaste
• Waste from overproduction
• Waste from waiting times
• Transportation waste
• Process Waste
• Inventory Waste
• Waste of motion
• Waste from product defects
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Figure 11.1Figure 11.1
Waste in OperationsWaste in Operations
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Figure 11.1Figure 11.1
Waste in OperationsWaste in Operations
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Figure 11.1Figure 11.1
Waste in OperationsWaste in Operations
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Common Causes of Common Causes of Waste Waste
• Layout (distance)
• Long setup time
• Incapable processes
• Poor maintenance
• Poor work methods
• Lack of training
• Inconsistent performance measures
• Ineffective production planning
• Lack of workplace organization
• Poor supply quality/reliability
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Objectives of JIT Objectives of JIT • Produce only the products the customer wants. • Produce products only at the rate that the customer
wants them. • Produce with perfect quality• Produce with minimum lead time.• Produce products with only those features the
customer wants. • Produce with no waste of labor, material or equipment
-- every movement must have a purpose so that there is zero idle inventory.
• Produce with methods that allow for the development of people
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Basic Elements of JITBasic Elements of JIT1.1. Flexible resourcesFlexible resources2.2. Cellular layoutsCellular layouts3.3. Pull production systemPull production system4.4. Kanban production controlKanban production control5.5. Small-lot productionSmall-lot production6.6. Quick setupsQuick setups7.7. Uniform production levelsUniform production levels8.8. Quality at the sourceQuality at the source9.9. Total productive maintenanceTotal productive maintenance10.10. Supplier networksSupplier networks
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Flexible ResourcesFlexible Resources
Multifunctional workersMultifunctional workersGeneral purpose machinesGeneral purpose machinesStudy operators & improve Study operators & improve
operationsoperations
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Standard Operating Routine Standard Operating Routine for a Workerfor a Worker
Standard Operating RoutineSheet 1
Worker: RussellCycle Time: 2 min
Order of Operations timeOperations :10 :20 :30 :40 :50 1:00 1:10 1:20 1:30 1:40 1:50 2:00
Pick up material
Unload/load machine 1
Unload/load machine 2
Unload/load machine 3
Inspect/pack
Figure 11.2Figure 11.2
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Cellular LayoutsCellular LayoutsGroup dissimilar machines in Group dissimilar machines in
manufacturing cell to produce manufacturing cell to produce family of partsfamily of parts
Work flows in one direction Work flows in one direction through cellthrough cell
Cycle time adjusted by changing Cycle time adjusted by changing worker pathsworker paths
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Manufacturing Cell with Manufacturing Cell with Worker RoutesWorker Routes
Worker Worker 11
Worker Worker 22
Worker Worker 33
Cell 1Cell 1
Figure 11.3Figure 11.3
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Worker Routes Lengthened Worker Routes Lengthened as Volume Decreasesas Volume Decreases
Cell 5Cell 5
Worker Worker 22
Cell 2Cell 2
Worker Worker 11
Cell 1Cell 1
Worker Worker 33
Cell 3Cell 3 Cell 4Cell 4
Figure 11.4Figure 11.4
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
JIT Principles JIT Principles • Create flow production • one piece flow
• machines in order of processes • small and inexpensive equipment • U cell layout, counter clockwise • multi-process handling workers • easy moving/standing operations • standard operations defined
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Balanced Production Balanced Production
• TAKT time
• Objective -- Build at rate that the customer wants work
• Balance the system to maximize efficiency at this rate
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
TAKT Time TAKT Time
• TAKT
• the beat
• (Net Available Operating Time) / Customer Requirements
• time periods must be consistent
• Example of calculation
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
TAKT Time Example TAKT Time Example • Net Available Operating Time • Time per shift 480´ • Breaks (2 @ 10´) - 20´ • Clean-up - 20 • Lunch - 30
• NAOT/shift 410´• Customer Requirements • Monthly 26,000 • No. Working Days 20
• CR/Day 1,300• T/T • 410´/shift*60"/min*3 shifts/1,300
• 56.769" per part or 57"
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
The Pull SystemThe Pull SystemMaterial is pulled through the system Material is pulled through the system
when neededwhen neededReversal of traditional push system Reversal of traditional push system
where material is pushed according where material is pushed according to a scheduleto a schedule
Forces cooperationForces cooperationPrevent over and underproductionPrevent over and underproduction
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Kanban Production Kanban Production Control SystemControl System
Kanban card indicates standard quantity Kanban card indicates standard quantity of productionof production
Derived from two-bin inventory systemDerived from two-bin inventory system Kanban maintains discipline of pull Kanban maintains discipline of pull
productionproduction Production kanban authorizes productionProduction kanban authorizes production Withdrawal kanban authorizes movement Withdrawal kanban authorizes movement
of goodsof goods
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
A Sample KanbanA Sample Kanban
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
The Origin of KanbanThe Origin of Kanbana) Two-bin inventory systema) Two-bin inventory system b) Kanban inventory systemb) Kanban inventory system
Reorder Reorder cardcard
Bin 1Bin 1
Bin 2Bin 2
Q - R
KanbanKanban
RR
QQ = order quantity = order quantity
RR = reorder point - demand during lead time = reorder point - demand during lead time
Figure 11.5Figure 11.5
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Types of KanbansTypes of Kanbans
Figure 11.6Figure 11.6
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Types of KanbansTypes of Kanbans
Figure 11.6Figure 11.6
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Types of KanbansTypes of Kanbans
Figure 11.6Figure 11.6
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Types of KanbansTypes of Kanbans Kanban SquareKanban Square
Marked area designed to hold itemsMarked area designed to hold items Signal KanbanSignal Kanban
Triangular kanban used to signal Triangular kanban used to signal production at the previous workstationproduction at the previous workstation
Material KanbanMaterial KanbanUsed to order material in advance of a Used to order material in advance of a
processprocess Supplier KanbansSupplier Kanbans
Rotate between the factory and suppliersRotate between the factory and suppliers
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Determining Number of Determining Number of KanbansKanbans
wherewhere
NN = number of kanbans or containers= number of kanbans or containersdd = average demand over some time period= average demand over some time periodLL = lead time to replenish an order= lead time to replenish an orderSS = safety stock= safety stockCC = container size= container size
No. of Kanbans =No. of Kanbans =average demand during lead time + safety stockaverage demand during lead time + safety stock
container sizecontainer size
NN = =dLdL + + SS
CC
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Determining the Number Determining the Number of Kanbansof Kanbansdd = 150 bottles per hour= 150 bottles per hourLL = 30 minutes = 0.5 hours= 30 minutes = 0.5 hoursSS = 0.10(150 x 0.5) = 7.5= 0.10(150 x 0.5) = 7.5CC = 25 bottles= 25 bottles
Round up to 4 (to allow some slack) or Round up to 4 (to allow some slack) or down to 3 (to force improvement)down to 3 (to force improvement)
NN = == =
= = 3.3 kanbans or containers= = 3.3 kanbans or containers
dLdL + + SSCC
(150 x 0.5) + 7.5(150 x 0.5) + 7.5
252575 + 7.575 + 7.5
2525
Example 11.1Example 11.1
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Small-Lot ProductionSmall-Lot Production
Requires less space & capital Requires less space & capital investmentinvestment
Moves processes closer togetherMoves processes closer togetherMakes quality problems easier to Makes quality problems easier to
detectdetectMakes processes more dependent Makes processes more dependent
on each otheron each other
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Inventory Hides ProblemsInventory Hides Problems
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Lower Levels of Inventory Lower Levels of Inventory Expose ProblemsExpose Problems
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Components of Lead TimeComponents of Lead TimeProcessing timeProcessing time
Reduce number of items or improve Reduce number of items or improve efficiencyefficiency
Move timeMove time Reduce distances, simplify Reduce distances, simplify
movements, standardizemovements, standardize routingsroutingsWaiting timeWaiting time
Better scheduling, sufficient capacityBetter scheduling, sufficient capacitySetup timeSetup time
Generally the biggest bottleneckGenerally the biggest bottleneck
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
KaizenKaizenContinuous improvementContinuous improvementRequires total employment Requires total employment
involvementinvolvementEssence of JIT is willingness of Essence of JIT is willingness of
workers toworkers toSpot quality problemsSpot quality problemsHalt production when necessaryHalt production when necessaryGenerate ideas for improvementGenerate ideas for improvementAnalyze problemsAnalyze problemsPerform different functionsPerform different functions
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Benefits of JITBenefits of JIT1.1. Reduced Reduced
inventoryinventory2.2. Improved qualityImproved quality3.3. Lower costsLower costs4.4. Reduced space Reduced space
requirementsrequirements5.5. Shorter lead timeShorter lead time6.6. Increased Increased
productivityproductivity7.7. Greater flexibilityGreater flexibility
8.8. Better relations Better relations with supplierswith suppliers
9.9. Simplified Simplified scheduling and scheduling and control activitiescontrol activities
10.10. Increased capacityIncreased capacity11.11. Better use of Better use of
human resourceshuman resources12.12. More product More product
varietyvariety
To Accompany Russell and Taylor, Operations Management, 4th Edition, 2003 Prentice-Hall, Inc. All rights reserved.
Use JIT to finely tune an Use JIT to finely tune an operating systemoperating system
Somewhat different in Somewhat different in USA than JapanUSA than Japan
JIT is still evolvingJIT is still evolvingJIT isn’t for everyoneJIT isn’t for everyone
JIT ImplementationJIT Implementation