Post on 29-Dec-2015
F-F-11
Applying Lean to Factory Applying Lean to Factory HomebuildingHomebuilding
Dr. Mike Mullens, PEDr. Mike Mullens, PE
F-F-22
Big Product with Many Large Big Product with Many Large ComponentsComponents
F-F-33
Few Small, Fixed WorkstationsFew Small, Fixed Workstations
F-F-44
Few Large, Fixed WorkstationsFew Large, Fixed Workstations
F-F-55
Many Large, Moving Many Large, Moving WorkstationsWorkstations
Labor and materials flow to Labor and materials flow to product while product flows product while product flows continuously on linecontinuously on line
Little inventory Little inventory because there is because there is no spaceno space
Line used to set Line used to set pace and facilitate pace and facilitate delivery of large delivery of large componentscomponents
F-F-66
Activity Location FlexibilityActivity Location Flexibility
Most operations after roof set can and do take Most operations after roof set can and do take place anywhere on line – as long as place anywhere on line – as long as precedence's are metprecedence's are met
F-F-77
Some Activities Can Stop the Some Activities Can Stop the LineLine
F-F-88
Value Added Value Added Continuously: Continuously: Often in Often in Parallel Parallel ActivitiesActivities
F-F-99
Massive Work ContentMassive Work Content
Multi-operator teams perform trade-focused Multi-operator teams perform trade-focused activitiesactivities
F-F-1010
Massive Work ContentMassive Work Content
Extended cycle timesExtended cycle times
Very difficult to measure work content and cycle Very difficult to measure work content and cycle time for any unittime for any unit
ModuleModule Wall LengthWall Length Wall Assembly Labor: Observed Man MinutesWall Assembly Labor: Observed Man Minutes Estimated Cycle Estimated Cycle Time (Min)Time (Min)
(Feet)(Feet) Value AddedValue Added Non Value Non Value AddedAdded
TotalTotal
2528 A2528 A 8585 252 (89%)252 (89%) 27 (11%)27 (11%) 252 (100%)252 (100%) 126126
2528 B2528 B 8989 294 (84%)294 (84%) 54 (16%)54 (16%) 348 (100%)348 (100%) 174174
Sub TotalSub Total 174174 519 (87%)519 (87%) 81 (13%)81 (13%) 600 (100%)600 (100%) 300300
2632 A2632 A 8383 264 (85%)264 (85%) 48 (15%)48 (15%) 312 (100%)312 (100%) 156156
2632 B2632 B 8080 348 (83%)348 (83%) 72 (17%)72 (17%) 420 (100%)420 (100%) 210210
Sub TotalSub Total 163163 612 (84%)612 (84%) 120 (16%)120 (16%) 732 (100%)732 (100%) 366366
TotalTotal 337337 1131 (85%)1131 (85%) 201 (15%)201 (15%) 1332 (100%)1332 (100%) 666666
F-F-1111
Product Built-to-Order: Varied Product Mix with Customization
F-F-1212
Product Built-to-Order: Varied Product Mix with Customization
F-F-1313
Product Built-to-Order: Varied Product Mix with Customization
F-F-1414
Product Built-to-Order: Varied Product Mix with Customization
F-F-1515
Product Built-to-Order: Varied Product Mix with Customization
F-F-1616
Product Built-to-Order: Varied Product Mix with Customization
F-F-1717
Product Built-to-Order: Varied Product Mix with Customization
F-F-1818
Product Built-to-Order: Varied Product Built-to-Order: Varied Product Mix with CustomizationProduct Mix with Customization
High process variability High process variability
F-F-1919
ModuleModule Wall Wall Length Length (Feet)(Feet)
Wall Assembly Labor: Observed Man Wall Assembly Labor: Observed Man MinutesMinutes
Estimated Estimated Cycle Time Cycle Time (Min)(Min)
Value AddedValue Added Non Value Non Value AddedAdded
TotalTotal
2528 A2528 A 8585 252 (89%)252 (89%) 27 (11%)27 (11%) 252 (100%)252 (100%) 126126
2528 B2528 B 8989 294 (84%)294 (84%) 54 (16%)54 (16%) 348 (100%)348 (100%) 174174
Sub TotalSub Total 174174 519 (87%)519 (87%) 81 (13%)81 (13%) 600 (100%)600 (100%) 300300
2632 A2632 A 8383 264 (85%)264 (85%) 48 (15%)48 (15%) 312 (100%)312 (100%) 156156
2632 B2632 B 8080 348 (83%)348 (83%) 72 (17%)72 (17%) 420 (100%)420 (100%) 210210
Sub TotalSub Total 163163 612 (84%)612 (84%) 120 (16%)120 (16%) 732 (100%)732 (100%) 366366
TotalTotal 337337 1131 (85%)1131 (85%) 201 (15%)201 (15%) 1332 (100%)1332 (100%) 666666
Product Built-to-Order: Varied Product Mix with Customization
High cycle time High cycle time variabilityvariabilityVery difficult to Very difficult to predict work predict work content and content and cycle time for cycle time for each activityeach activityNot easy to Not easy to control control line balanceline balance
F-F-2020
Cycle vs. TAKT TimeCycle vs. TAKT Time
Average cycle time for each activity must be less Average cycle time for each activity must be less than TAKT timethan TAKT time
Activity with largest average cycle time is Activity with largest average cycle time is bottleneck activity bottleneck activity
If bottleneck activity is delayed, line capacity is If bottleneck activity is delayed, line capacity is lost – can happen even if average cycle less lost – can happen even if average cycle less than TAKT timethan TAKT time
F-F-2121
Seeing the Waste (and the Seeing the Waste (and the Opportunity)Opportunity)
Constant imbalance in labor & work contentConstant imbalance in labor & work content
Production mistakesProduction mistakes
Design oversightsDesign oversights
Material Material shortages shortages
Materials45-50%
Labor10-15%
Overhead35-45%
F-F-2222
Floating Bottlenecks: Imbalance in Floating Bottlenecks: Imbalance in Labor and Work Content Labor and Work Content
Upstream Queue - FloorsUpstream Queue - Floors
F-F-2323
Floating Bottlenecks: Imbalance in Floating Bottlenecks: Imbalance in Labor and Work Content Labor and Work Content
Downstream line starvation – drywall finishing Downstream line starvation – drywall finishing and interior finishingand interior finishing
F-F-2424
Floating Bottlenecks: Imbalance in Floating Bottlenecks: Imbalance in Labor and Work Content Labor and Work Content
Other Impacts:Other Impacts:– Hurry Hurry exhaustion, frustration, rework exhaustion, frustration, rework
– Overtime Overtime higher costs, turnover higher costs, turnover
– Unfinished work in yardUnfinished work in yard
– Lost production capacityLost production capacity
F-F-2525
Value-Added vs. Non-Value Added Value-Added vs. Non-Value Added TimeTime
ModuleModule Wall Wall LengthLength
Observed Man MinutesObserved Man Minutes Estimated Man Estimated Man MinMin
(Feet)(Feet) Value AddedValue Added Non Value Non Value AddedAdded
TotalTotal
2528 A2528 A 8585 252 (89%)252 (89%) 27 (11%)27 (11%) 252 (100%)252 (100%) 358 (142%)358 (142%)
2528 B2528 B 8989 294 (84%)294 (84%) 54 (16%)54 (16%) 348 (100%)348 (100%) 371 (106%)371 (106%)
Sub TotalSub Total 174174 519 (87%)519 (87%) 81 (13%)81 (13%) 600 (100%)600 (100%) 729 (122%)729 (122%)
2632 A2632 A 8383 264 (85%)264 (85%) 48 (15%)48 (15%) 312 (100%)312 (100%) 349 (112%)349 (112%)
2632 B2632 B 8080 348 (83%)348 (83%) 72 (17%)72 (17%) 420 (100%)420 (100%) 337 (80%)337 (80%)
Sub TotalSub Total 163163 612 (84%)612 (84%) 120 (16%)120 (16%) 732 (100%)732 (100%) 686 (94%)686 (94%)
TotalTotal 337337 1131 (85%)1131 (85%) 201 (15%)201 (15%) 1332 (100%)1332 (100%) 1415 (106%)1415 (106%)
F-F-2626
Operations Process Chart with Operations Process Chart with Work MeasurementWork Measurement
100282.7348.2263.5294225Total
618.020172312Remove wall/walls from jig using crane18
13.06006Put plastic cover on wall if needed using stapler17
25.26.75554Remove screws that have missed studs or subassemblies using screwdriver
16
616.72420149Screwing sheetrock/firewall to wall using electrical screwdriver
15
1439.048444024Attach sheetrock/firewall to wall with nails14
411.2191268Put glue on studs and subassemblies13
11.50033Staple foil tape if required by state law using stapler
12
13.04332Puts nails on mark from string using hammer11
25.256.53.565Make horizontal mark with string for sheetrock/firewall placement
10
513.016121212Square wall9
1131.235303426Measure and cut sheetrock and/or firewall where needed
8
926.533232525Nail top plate/plates to studs and subassemblies using nailgun
7
926.033243017Nail bottom plate to studs and subassemblies using nailgun
6
1029.537233127Place subassemblies and/or studs on bottom plate5
26.810575Cut length of top and bottom plate4
925.736242221Measure length of top and bottom plate, and mark on bottom plate where to place subassemblies
3
411.51412812Place top and bottom plates on jig2
39.506257Review drawing. Decide what walls to build.1
% age2632 B2632 A2528 B2528 ASequence
Avg. Man MinMAN MINTaskTask
100282.7348.2263.5294225Total
618.020172312Remove wall/walls from jig using crane18
13.06006Put plastic cover on wall if needed using stapler17
25.26.75554Remove screws that have missed studs or subassemblies using screwdriver
16
616.72420149Screwing sheetrock/firewall to wall using electrical screwdriver
15
1439.048444024Attach sheetrock/firewall to wall with nails14
411.2191268Put glue on studs and subassemblies13
11.50033Staple foil tape if required by state law using stapler
12
13.04332Puts nails on mark from string using hammer11
25.256.53.565Make horizontal mark with string for sheetrock/firewall placement
10
513.016121212Square wall9
1131.235303426Measure and cut sheetrock and/or firewall where needed
8
926.533232525Nail top plate/plates to studs and subassemblies using nailgun
7
926.033243017Nail bottom plate to studs and subassemblies using nailgun
6
1029.537233127Place subassemblies and/or studs on bottom plate5
26.810575Cut length of top and bottom plate4
925.736242221Measure length of top and bottom plate, and mark on bottom plate where to place subassemblies
3
411.51412812Place top and bottom plates on jig2
39.506257Review drawing. Decide what walls to build.1
% age2632 B2632 A2528 B2528 ASequence
Avg. Man MinMAN MINTaskTask
F-F-2727
Non-Value Added ActivitiesNon-Value Added ActivitiesTaskTask MAN MINMAN MIN Tot. Man MinTot. Man Min
2528 A2528 A 2528 B2528 B 2632 A2632 A 2632 B2632 B %%
UnknownUnknown 1212 2020 22.522.5 11.7511.75 66.2566.25 3434
Rebuild window subassemblyRebuild window subassembly 2424 2424 1212
Cut sheetrock for other workstationCut sheetrock for other workstation 2222 2222 1111
Helping roof jigHelping roof jig 22 1717 1919 1010
Paper workPaper work 1717 1717 99
Out of nails and glueOut of nails and glue 1212 1212 66
Move modules on-lineMove modules on-line 88 88 44
Helping wall setHelping wall set 33 44 77 44
Worker hurt by nailgunWorker hurt by nailgun 77 77 44
Order sheetrockOrder sheetrock 77 77 44
Clean-upClean-up 44 44 22
Moving pile of sheetrockMoving pile of sheetrock 22 22 11
Carry bathtub to wall set areaCarry bathtub to wall set area 22 22 11
Total:Total: 2323 5454 48.548.5 7171 197197 100100
F-F-2828
House No. 2 5 8 11 14 17 20 23 26 29 2 5 8 11 14 17 20 23 26 29 1 4 7 10 13 16 19 22 25 28 1 4 7 10 13 16 19 22 25 28 31 3 6 9 12 15 18 21 24 27 30 2 5 8 11 14 17 20 23
2201 12204 022242256 42258 118712212 4 22220 32230 722382254 322232267 12231213622502262223622392264 # 2 0221922402233219322702274 022602275228122152280225122762192 #226322792277228322892297230022982290 22293 112299
February
Production Cycle Times
841902
September October November December
8842
333
January
1526
54734
478516
686450 34
866471
517
474605
853438
902231
776 94
441 22
478 16471
298
5734
643555 5
53499
51570 85
475495
438 52
1149 91
766 69
211147
460 39 18 14
30402
328338 346
5
515
489853
410
12
22
136182
317577
Production ScheduleProduction Schedule
F-F-2929
Distribution of Production Cycle Times
0
2
4
6
8
10
12
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
Duration per House (Weeks)
Nu
mb
er o
f H
ou
ses
Avg. 8 weeks
Production Cycle TimesProduction Cycle Times
F-F-3030
ReworkRework
Rework
0 5 10 15 20 25
Shop II
Deck Jig
Wall Jig
Wall Set
Roof Table
Roof Set
Rough Electric
Rough Plumbing
Sheetrock
Sheathing
Roofing
Doors & Windows
Siding
Taping
Sand & Paint
Finish Electric
Door Shop
Trim
Cabinets
Countertops
Painting
Finish Floater
Quality Control
Clean-up
Shop III
Acti
vit
y
% of Total Hours Worked
44%
Avg. = 7%
F-F-3131
ReworkRework
Labor wasteLabor waste
Service problemsService problems
Line variabilityLine variability
F-F-3232
ReworkRework
F-F-3333
Lean Construction PrinciplesLean Construction Principles
Keep activities flowing, particularly along critical Keep activities flowing, particularly along critical path and bottleneck activitiespath and bottleneck activities
Remove uncertainty and variability, especially Remove uncertainty and variability, especially along critical path and bottleneck activitiesalong critical path and bottleneck activities
F-F-3434
Lean Construction ApproachLean Construction Approach
Improve quality of task assignmentsImprove quality of task assignments
Be sure preceding activities are complete, task Be sure preceding activities are complete, task well documented, and materials and tools are well documented, and materials and tools are availableavailable
F-F-3535
Lean Construction Problem Lean Construction Problem MitigationMitigation
Plan buffers – backlog of activities for crews Plan buffers – backlog of activities for crews (queues of work ready to be done – adding to (queues of work ready to be done – adding to length of critical path and thus to production line)length of critical path and thus to production line)
Surge piles – raw and WIP materialsSurge piles – raw and WIP materials
Flexible capacity – intentionally underutilized Flexible capacity – intentionally underutilized crews or flexible use of cross-trained workerscrews or flexible use of cross-trained workers