ch15 Operation Management Roberta Russell & Bernard W. Taylor

(1)

Beni Asllani Beni Asllani Beni Asllani Beni Asllani Lean Production Lean Production Lean Production Lean Production Operations Management - 5

Operations Management - 5 th th _Edition_Edition

Chapter 15

Roberta Russell & Bernard W. Taylor, III Roberta Russell & Bernard W. Taylor, III Roberta Russell & Bernard W. Taylor, III

(2)

Lecture Outline



 _{Basic Elements of Lean Production}_{Basic Elements of Lean Production}



 _{Benefits of Lean Production}_{Benefits of Lean Production}



 Implementing Lean ProductionImplementing Lean Production



(3)

Lean Production



 _{Doing more with less inventory, fewer}_{Doing more with less inventory, fewer}

workers, less space



 _{Just-in-time (JIT)}_{Just-in-time (JIT)}



 smoothing thesmoothing the flow flow of material to arriveof material to arrive just as it is needed

just as it is needed 

 “JIT” and “Lean Production” are used“JIT” and “Lean Production” are used interchangeably

interchangeably



 _Muda_Muda



 waste, anything other than that whichwaste, anything other than that which adds value to the product or service

(4)

Waste in Operations

(5)

Waste in Operations (cont.)

(6)

Waste in Operations (cont.)

(7)

Basic Elements

1. 1. FFlelexixiblble e reresosoururcecess 2. 2. CCelellululalar r lalayoyoututss 3. 3. PuPull ll prprododucuctition on sysyststemem 4. 4. KaKanbnban an prprododucuctition on cocontntroroll 5. 5. SmSmalall l lolot t prprododucuctitionon 6 6. . QQuuiicck k sseettuuppss 7. 7. UnUnififororm m prprododucuctition on lelevevelsls 8. 8. TTototal al prprododucuctitiveve maintenance maintenance 9. 9. SSupupplplieier r nenettwoworkrkss

(8)

Flexible Resources



 _{Multifunctional workers}_{Multifunctional workers}



 perform more than one jobperform more than one job



 general-purpose machines performgeneral-purpose machines perform several basic functions

several basic functions



 Cycle timeCycle time



 time required for the worker to completetime required for the worker to complete one pass through the operations

one pass through the operations

assigned



 _{Takt time}_{Takt time}



(9)

Standard Operating

Routine for a Worker

(10)

Cellular Layouts



 _{Manufacturing cells}_{Manufacturing cells}



 comprised of dissimilar machines broughtcomprised of dissimilar machines brought together to manufacture a family of parts

together to manufacture a family of parts



 Cycle time is adjusted to match takt timeCycle time is adjusted to match takt time

by changing worker paths

(11)

Cells with Worker Routes

(12)

Worker Routes Lengthen as

Volume Decreases

(13)

Pull System



 _{Material is pulled through the system when}_{Material is pulled through the system when}_{Material is pulled through the system when}_{Material is pulled through the system when}

needed needed needed

needed



 _{Reversal of traditional push system where}_{Reversal of traditional push system where}_{Reversal of traditional push system where}_{Reversal of traditional push system where}

material is pushed according to a schedule material is pushed according to a schedule material is pushed according to a schedule

material is pushed according to a schedule



 _{Forces cooperation}_{Forces cooperation}_{Forces cooperation}_{Forces cooperation}



 _{Prevent over and underproduction}_{Prevent over and underproduction}_{Prevent over and underproduction}_{Prevent over and underproduction}



 While push systems rely on a predeterminedWhile push systems rely on a predetermined

schedule, pull systems rely on customer

requests

(14)

Kanbans



 _{Card which indicates standard quantity}_{Card which indicates standard quantity}_{Card which indicates standard quantity}_{Card which indicates standard quantity}

of production of production of production

of production



 Derived from two-bin inventory systemDerived from two-bin inventory system_{Derived from two-bin inventory system}_{Derived from two-bin inventory system}



 _{Maintain discipline of pull production}_{Maintain discipline of pull production}_{Maintain discipline of pull production}_{Maintain discipline of pull production}



 _{Authorize production and movement of}_{Authorize production and movement of}_{Authorize production and movement of}_{Authorize production and movement of}

goods goods goods

(15)

Sample Kanban

(16)

Origin of Kanban

a) Two-bin inventory system a) Two-bin inventory system a) Two-bin inventory system

a) Two-bin inventory system b) Kanban inb) Kanban inb) Kanban inb) Kanban inventory systemventory systemventory systemventory system

Reorder Reorder Reorder Reorder card card card card Bin 1 Bin 1 Bin 1 Bin 1 Bin 2 Bin 2 Bin 2 Bin 2 Q Q _-_- R R Kanban Kanban Kanban Kanban R R R R Q Q Q

Q _{= order quantity}_{= order quantity}_{= order quantity}_{= order quantity}

R R R

(17)

Types of Kanban



 _{Production kanban}_{Production kanban}



 authorizes production ofauthorizes production of goods

goods



 Withdrawal kanbanWithdrawal kanban



 authorizes movement ofauthorizes movement of goods

goods



 Kanban squareKanban square



 a marked area designateda marked area designated to hold items

to hold items



 _{Signal kanban}_{Signal kanban}



 a triangular kanbana triangular kanban used to signal used to signal production at the production at the previous workstation previous workstation 

 Material kanbanMaterial kanban



 used to order material inused to order material in advance of a process

advance of a process



 _{Supplier kanban}_{Supplier kanban}



 rotates between therotates between the factory and suppliers

(18)

(19)

(20)

(21)

Determining Number of

Kanbans

where where where where N N N

N _{= number of kanbans or containers}_{= number of kanbans or containers}_{= number of kanbans or containers}_{= number of kanbans or containers}

d d d

d _{= average demand over some time period}_{= average demand over some time period}_{= average demand over some}_{= average demand over some time period}_{time period}

L L L

L _{= lead time to replenish an order}_{= lead time to replenish an order}_{= lead time to replenish an order}_{= lead time to replenish an order}

S S S

S _{= safety stock}_{= safety stock}_{= safety stock}_{= safety stock}

C C C

C _{= container size}_{= container size}_{= container size}_{= container size}

No. of Kanbans = No. of Kanbans = No. of Kanbans =

No. of Kanbans = average demand during lead time + safety stockaverage demand during lead time + safety stockaverage demand during lead time + average demand during lead time + safety stocksafety stock

container size container size container size container size N N N N ₌₌₌₌ dLdLdLdL ++++ S S S S C C C C

(22)

Determining Number of

Kanbans: Example

d d d

d _{= 150 bottles per hour}_{= 150 bottles per hour}_{= 150 bottles per hour}_{= 150 bottles per hour}

L L L

L _{= 30 minutes = 0.5 hours}_{= 30 minutes = 0.5 hours}_{= 30 minutes = 0.5 hours}_{= 30 minutes = 0.5 hours}

S S S S _{= 0.10(150 x 0.5) = 7.5}_{= 0.10(150 x 0.5) = 7.5}_{= 0.10(150 x 0.5) = 7.5}_{= 0.10(150 x 0.5) = 7.5} C C C

C _{= 25 bottles}_{= 25 bottles}_{= 25 bottles}_{= 25 bottles}

Round up to 4 (to allow some slack) or Round up to 4 (to allow some slack) or 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) down to 3 (to force improvement)

down to 3 (to force improvement)

N N N

N ₌₌₌₌ ₌₌₌₌

=

= = = 3.3 3.3 kanbans kanbans or or containerscontainers =

= = = 3.3 3.3 kanbans kanbans or or containerscontainers

dL dL dL dL ₊₊₊₊ S S S S C C C C (150 x 0.5) + 7.5 (150 x 0.5) + 7.5 (150 x 0.5) + 7.5 (150 x 0.5) + 7.5 25 25 25 25 75 + 7.5 75 + 7.5 75 + 7.5 75 + 7.5 25 25 25 25

(23)

Small Lots



Require less space and capital

_{Require less space and capital}

investment



Move processes closer together

_{Move processes closer together}



_{Make quality problems easier to}

detect



Make processes more dependent

_{Make processes more dependent}

on each other

(24)

Inventory Hides Problems

(25)

Less Inventory Exposes Problems

(26)

Components of Lead Time



 _{Processing time}_{Processing time}_{Processing time}_{Processing time}



 Reduce number of items or improve efficiencyReduce number of items or improve efficiencyReduce number of items or improve efficiencyReduce number of items or improve efficiency



 _{Move time}_{Move time}_{Move time}_{Move time}



 Reduce distances, simplify movements, standardizeReduce distances, simplify movements, standardizeReduce distances, simplify movements, standardizeReduce distances, simplify movements, standardize routings

routings routings

routings



 _{Waiting time}_{Waiting time}_{Waiting time}_{Waiting time}



 Better scheduling, sufficient capacityBetter scheduling, sufficient capacityBetter scheduling, sufficient capacityBetter scheduling, sufficient capacity



 _{Setup time}_{Setup time}_{Setup time}_{Setup time}



(27)

Quick Setups



 _{Internal setup}_{Internal setup}_{Internal setup}_{Internal setup}



 Can be performedCan be performedCan be performedCan be performed

only when a only when a only when a only when a process is stopped process is stopped process is stopped process is stopped 

 _{External setup}_{External setup}_{External setup}_{External setup}



 Can be performedCan be performedCan be performedCan be performed

in advance in advance in advance

in advance



 _{SMED Principles}_{SMED Principles}_{SMED Principles}_{SMED Principles}



 Separate internal setup fromSeparate internal setup fromSeparate internal setup fromSeparate internal setup from

external setup external setup external setup

external setup



 Convert internal setup to externalConvert internal setup to externalConvert internal setup to externalConvert internal setup to external

setup setup setup

setup



 Streamline all aspects of setupStreamline all aspects of setupStreamline all aspects of setupStreamline all aspects of setup



 Perform setup activities inPerform setup activities inPerform setup activities inPerform setup activities in

parallel or eliminate them entirely parallel or eliminate them entirely parallel or eliminate them entirely

(28)

Common Techniques for Reducing

Setup Time

(29)

Common Techniques for Reducing

Setup Time (cont.)

(30)

Common Techniques for Reducing

Setup Time (cont.)

(31)

Uniform Production Levels



 _{Result from smoothing production}_{Result from smoothing production}

requirements



 _{Kanban systems can handle +/- 10%}_{Kanban systems can handle +/- 10%}_{Kanban systems can handle +/- 10%}_{Kanban systems can handle +/- 10%}

demand changes demand changes demand changes

demand changes



 Smooth demand across planningSmooth demand across planning_{Smooth demand across planning}_{Smooth demand across planning}

horizon horizon horizon

horizon



 Mixed-model assembly steadiesMixed-model assembly steadies_{Mixed-model assembly steadies}_{Mixed-model assembly steadies}

component production component production component production

(32)

Mixed-Model Sequencing

(33)

Quality at the Source



 Visual controlVisual control



 makes problems visiblemakes problems visible



 _Poka-yokes_Poka-yokes



 prevent defects fromprevent defects from

occurring



 _Kaizen_Kaizen



 a system of continuousa system of continuous

improvement; “change for

the good of all”



 JidokaJidoka



 authority to stop theauthority to stop the

production line



 _Andons_Andons



 call lights that signalcall lights that signal

quality problems quality problems   _{Under-capacity}_{Under-capacity} scheduling scheduling 

 leaves time for planning,leaves time for planning,

problem solving, and

maintenance

(34)

Examples of Visual

Control

(35)

Examples of Visual

Control (cont.)

(36)

Examples of Visual

Control (cont.)

(37)

Total Productive

Maintenance (TPM)



Breakdown maintenance

_{Breakdown maintenance}



 Repairs to make failed machine operationalRepairs to make failed machine operationalRepairs to make failed machine operationalRepairs to make failed machine operational



_{Preventive maintenance}



 System of periodic inspection andSystem of periodic inspection andSystem of periodic inspection andSystem of periodic inspection and

maintenance to keep machines operating maintenance to keep machines operating maintenance to keep machines operating

maintenance to keep machines operating



TPM combines preventive maintenance

_{TPM combines preventive maintenance}

and total quality concepts

(38)

TPM Requirements



 _{Design products that can be easily produced}_{Design products that can be easily produced}_{Design products that can be easily produced}_{Design products that can be easily produced}

on existing machines on existing machines on existing machines

on existing machines



 _{Design machines for easier operation,}_{Design machines for easier operation,}_{Design machines for easier operation,}_{Design machines for easier operation,}

changeover, maintenance changeover, maintenance changeover, maintenance

changeover, maintenance



 _{Train and retrain workers to operate machines}_{Train and retrain workers to operate machines}_{Train and retrain workers to operate machines}_{Train and retrain workers to operate machines}



 _{Purchase machines that maximize productive}_{Purchase machines that maximize productive}_{Purchase machines that maximize productive}_{Purchase machines that maximize productive}

potential potential potential

potential



 _{Design preventive maintenance plan spanning}_{Design preventive maintenance plan spanning}_{Design preventive maintenance plan spanning}_{Design preventive maintenance plan spanning}

life of machine life of machine life of machine

(39)



Unneeded equipment, tools, furniture;Unneeded equipment, tools, furniture;

unneeded items on walls, bulletins; items

blocking aisles or stacked in corners;

unneeded inventory, supplies, parts; safety

hazards



Items not in their correct places; Items not in their correct places; correctcorrect

places not obvious; aisles, workstations, &

equipment locations not indicated; items not

put away immediately after use



Floors, walls, stairs, equipment, & surfacesFloors, walls, stairs, equipment, & surfaces

not lines, clean; cleaning materials not easily

accessible; labels, signs broken or unclean;

Supplier Networks



 _{Long-term supplier contracts}_{Long-term supplier contracts}



 _{Synchronized production}_{Synchronized production}



 Supplier certificationSupplier certification



 _{Mixed loads and frequent deliveries}_{Mixed loads and frequent deliveries}



 Precise delivery schedulesPrecise delivery schedules



 Standardized, sequenced deliveryStandardized, sequenced delivery



(41)

Benefits of Lean

Production



 Reduced inventoryReduced inventory



 _{Improved quality}_{Improved quality}



 _{Lower costs}_{Lower costs}



 Reduced space requirementsReduced space requirements



 _{Shorter lead time}_{Shorter lead time}



(42)

Benefits of Lean

Production (cont.)



 _{Greater flexibility}_{Greater flexibility}



 _{Better relations with suppliers}_{Better relations with suppliers}



 Simplified scheduling and control activitiesSimplified scheduling and control activities



 Increased capacityIncreased capacity



 _{Better use of human resources}_{Better use of human resources}



(43)

Implementing Lean Production



Use lean production to finely tune an

_{Use lean production to finely tune an}

operating system



_{Somewhat different in USA than Japan}



_{Lean production is still evolving}



(44)

Lean Services



Basic elements of lean

_{Basic elements of lean}

production apply equally to

services



_{Most prevalent applications}



 lean retailinglean retailing 

 lean bankinglean banking 

(45)

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