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Stephen Hassler Jeffrey Troester University of Nebraska – Lincoln Department of Industrial & Management System Engineering Presented on April 15, 2009. Restoration of One-Piece Flow To Lincoln Industries. Contributors. Adventure Manufacturing, Inc. (OK) Franek Laser & Fab Systems (MN) - PowerPoint PPT Presentation
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RESTORATION OF ONE-PIECE FLOW
TO LINCOLN INDUSTRIESStephen Hassler
Jeffrey TroesterUniversity of Nebraska – Lincoln
Department of Industrial & Management System Engineering
Presented on April 15, 2009
ContributorsAdventure Manufacturing, Inc. (OK)Franek Laser & Fab Systems (MN)
Duane Franek – OwnerHotsy Equipment Co. (NE)
Roy Gage – Sales Representative Dennis Klingemann – Sales Representative
Lincoln Industries (NE) Bill Hancock – Area Leader, Fabrication Eric Jacobs – Development Engineer
North American Cutting Systems (CA)
Images: www.adventureinmetals.com, www.franeklaser.com, www.hotsy.com
INTRODUCTIONCompany Profile, Project Field, Problems, & Objective
Company ProfileIn 1952, Lincoln Industries was founded in
Lincoln, NE as a small job shop for custom electroplating.
The company has grown to become Lincoln’s largest water user and North America’s largest metal finisher.
In its 500,000 square feet of production and warehouse space, approximately 500 people are employed.
Annual revenues have grown rapidly over the past decade and now exceed $100 million.
Images: www.lincolnindustries.com
Project FieldLincoln Industries (LI) is
best known as North America’s largest metal finisher. However, the company’s operations are diverse and our team took a look at their fabrication activities. At a facility in Air Park (Lincoln, NE), LI fabricates exhaust stacks for semi-trailer trucks.
Images: www.lincolnchrome.com
Original ProblemUnfortunately, after the
production line was designed, installed, and operating, quality issues arose. A set of operations occurring early in the production sequence was causing damage to the parts.
Original RemedyA quick solution was developed
by LI and another operation was added to the production process, though it occurred on a workstation off of the main production line.
Consequential ProblemBy locating the workstation off of
the main line, one-piece flow was disrupted. As a result, material handling became excessive, processing time increased, and quality control declined.
Project ObjectiveIt is the goal of the investigating
team to develop a cost-effective proposal that remedies these undesirable byproducts and restores one-piece flow to the production line.
STUDY DETAILSAnalysis Method & Findings
Four Step Analysis MethodUnderstand Problem and
Magnitude Visual Aids, Quality Inspection, Time
StudiesDevelop Alternatives
Seek Expert Opinions, Creative Brainstorming
Verify Feasibility of Alternatives Examine Attributes and Costs, Design
ExperimentsEvaluate Alternatives
Economic Analysis, Discuss Qualitative Factors
Understand Problem and MagnitudeVisual Aids
The team developed a simple facility layout diagram to convey the problematic nature of the current arrangement.
Photographs and video were taken to document the process and highlight production issues.
Current LayoutSAW
DEBUR
CARTS
BEND
WASH
EMPTYAREA
(90 FT2)
≈ 100 FT
Lean IssuesFour of the Seven Wastes of the
Toyota Production System (TPS) were glaringly obvious as a result of the current layout.
Waste of Transportation Waste of Waiting Waste of Inventory Waste of Motion
Photographs
SAW
LOADING SAW
RAW MATERIAL
DEBURR MACHINEImages: www.lincolnchrome.com
PhotographsCHIPS
CHIPS
CART CARTS
PhotographsWASHWASH
BEND MACHINE
UNLOADING BENDERImages: www.lincolnchrome.com
Understand Problem and MagnitudeQuality Inspection
Though inefficient, the current wash operation sufficiently removes chips from the tubes.
Chips are being introduced from various sources such as material handling carts, gloves, rags, and tools.
Understand Problem and MagnitudeTime Studies
Surprisingly, the inefficient wash operation is not typically the bottleneck of the production line.
However, when the wash operation becomes congested, it definitely has the ability to function as the bottleneck.
Saw and Deburr OperationTime Study Results
Mean/Median/Mode Unit Times = 49 s / 43 s / 44 s
Minimum/Maximum Unit Times = 34 s / 82 s
Key Observations Excessive Work-in-Process (WIP) Buildup
(25+ Tubes) Operator Sets Operation Pace Insignificant Operator Idle Time Not Typically the Bottleneck Operation
Wash OperationTime Study Results
Unit Times = 36 s (for 25) / 43 s (for 15)
TOTAL 900 s (See Below)Move Cart to Wash Station 20 sIdle - (Often > 100 s)Lift Cart with Crane and Dunk in Bath
120 s
Cart Air Dry and Release from Crane
100 s
Hand Wipe (25) Tubes 640 sIdle - (Often > 100 s)
Move Cart to Bend Operation 20 s
Wash OperationKey Observations
Excessive Idle Time Frequently Congested Workstation Operator Sets Operation Pace Potentially the Bottleneck Operation
Bend OperationTime Study Results
Mean/Median/Mode Unit Times = 88 s / 82 s / 68 s
Minimum/Maximum Unit Times = 66 s / 133 s
Key Observations Machine Sets Operation Pace Minimal Operator Idle Time Potentially the Bottleneck Operation
Develop AlternativesSeek Expert Opinions
The first technique for developing alternatives was to conduct interviews with LI management and assemble the ideas that had already been considered.
LI management had considered two types of solutions. Those that washed parts and those that did not generate chips in the first place.
Two wash systems included power washing cabinets and power washing conveyor systems.
To eliminate chips altogether, laser cutting, abrasive water jet cutting, and precision saws were considered.
Develop AlternativesCreative Brainstorming
The second technique for developing alternatives was to do some “thinking outside of the box”. The team considered several unorthodox chip removal procedures.
The team considered only solutions that washed parts.
Use of vacuums and magnets were considered. Both in handheld and fixed configurations. Also, a simple water bath with drying fans was considered.
Develop AlternativesSeek Expert Opinion – Idea List
Power Washing Cabinet Power Washing Conveyor System Laser Cutting (No Chips) Abrasive Water Jet Cutting (No Chips) Precision Saw (No Chips)
Creative Brainstorming – Idea List Vacuum (Handheld or Fixed) Magnets (Handheld or Fixed) Water Bath with Drying Fans
Verify Feasibility of AlternativesExamine Attributes and Costs
The team first considered whether or not each alternative would accomplish the intended purpose.
Cost data was then used to eliminate some alternatives. Due to current economic conditions (including recent layoffs at LI), most high cost alternatives were deemed infeasible.
Design Experiments The team was forced to design
experiments in some cases to verify alternative feasibility.
Power Washing CabinetAttributes
Sufficiently Cleans Parts (Prior Testing at LI) Fits in Space between Saw and Bend
Operation No Labor to Dry Parts, Flash-Dry (60 s) Smaller Batches
Drawbacks Purchase Price = $10,650 Still Batching Parts Operating Costs, Consumables,
Maintenance
Power Washing Conveyor System
Attributes Fits in Space between Saw and Bend
Operation Transports Parts from Saw to Bend
Operation Pure One-Piece Flow
Drawbacks Purchase Price = $20,000 to $30,000 Unlikely to Effectively Clean Tube Interior Operating Costs, Consumables,
Maintenance Labor to Dry Parts Slip Hazards
Photographs
Images: www.adventureinmetals.com, www.globalspec.com
POWER WASHING CABINET
POWER WASHING CONVEYOR SYSTEM
Laser CuttingAttributes
No Metal Chips Eliminates Need for Deburr Operation Eliminates Need for Wash Operation Precision Cuts Cuts Harder Materials (Stainless Steel)
Drawbacks Purchase Price = $300,000 to $400,000 Operating Costs, Consumables,
Maintenance Hazardous Fumes
Abrasive Water Jet CuttingAttributes
No Metal Chips Eliminates Need for Deburr Operation Eliminates Need for Wash Operation
Drawbacks Purchase Price = $200,000 to $300,000 Operating Costs, Consumables, Maintenance Slower than Laser Cutting Requires Abrasive Particles in Water to Cut Abrasive Particles Necessitate Machine
Cleaning
Photographs
Images: www.advancedwaterjet.com, www.alspi.com
ABRASIVE WATER JET CUTTING
LASER CUTTING
Precision SawAttributes
No Metal Chips Eliminates Need for Deburr Operation Eliminates Need for Wash Operation Cuts Harder Materials (Stainless Steel)
Drawbacks Purchase Price = $400,000+ Operating Costs, Consumables,
Maintenance
Verify Feasibility of AlternativesList of Experiments Designed
Vacuum (Handheld or Fixed) Magnets (Handheld or Fixed) Water Bath with Drying Fans
PhotographsWATER BATH
VACUUMMAGNETS
Verify Feasibility of AlternativesResults of Experiments
Vacuum – Time Consuming, Only Fair Cleaning
Magnets – Time Consuming, Poor Cleaning
Water Bath and Drying Fans – Poor Cleaning, Slow Drying
Verify Feasibility of Alternatives
ALTERNATIVE FEASIBILITY DETERMINATION
Power Washing Cabinet FeasiblePower Washing Conveyor System
Infeasible – Poor Cleaning
Laser Cutting Infeasible – CostAbrasive Water Jet Cutting Infeasible – CostPrecision Saw Infeasible – CostVacuum (Handheld or Fixed) Infeasible – Poor CleaningMagnets (Handheld or Fixed) Infeasible – Poor CleaningWater Bath with Drying Fans Infeasible – Poor Cleaning
Evaluate AlternativesEconomic Analysis
Cost savings are likely to result from reduced labor (drying tubes), reduced overall processing time (from elimination of idle time), reduced WIP, potentially improved quality, and a cleaner, more orderly work space.
Will the savings from the installation of a power washing cabinet justify its expense?
PROPOSAL DETAILSDescription & Benefits
ProposalPurchase the Power Washing
CabinetInstall it in the Empty Space
between the Saw and Bend Operation
Wash the Tubes in Batches of 5Wash the Tubes for 120 sLet the Tubes Dry for 60 sSpend Minimally on Consumable,
Only Enough to Inhibit Washer Rusting
PhotographsPOWER WASHING
CABINETHOTSY MODEL 7663
Images: www.hotsy.com
Current LayoutSAW
DEBUR
CARTS
BEND
WASH
EMPTYAREA
(90 FT2)
≈ 100 FT
Proposed LayoutSAW
DEBUR
CARTS
BEND
WASH
WASH
≈ 10 FT
RationaleMoving water seems to remove
chips from the tubes better than other methods. For a relatively low cost, the team believes that LI can achieve significant savings with the installation of a power washing cabinet. However, the efficiency of the machine is dependent upon some batching. Therefore, pure one-piece flow will not be achieved.
Proposal Quote from HotsyPurchase Cost
$10, 650Tube Fixtures (5)
$1,250Consumables
$1,200 / YearTOTAL – YEAR 1
$13,100
Proposed ProcessPower Washing Cabinet
Batch Size: 5 Tubes Wash Phase: 120 s Dry Phase: 60 s Unload Phase: 50 s
Key Assumptions Saw Operation Unit Time Increases (5 s)
for Added Material Handling Bend Operation Unit Time Increases (10
s) for Added Material Handling
Processing Time ComparisonCurrent Process
25 Tubes 72 min + Wash Station Idle Time 15 Tubes 45 min + Wash Station Idle
TimeProposed Process
25 Tubes 74 min 15 Tubes 45 min
Key Observations Excessive Idle Time at Wash is Controlled No Significant Changes to Ideal Processing
Times
Labor SavingsKey Assumptions
Labor Expense (Hourly) = $15Source of Labor Savings
Labor Reduction at Wash Operation (1 Operator) Idle Time Avoidance at Wash Operation (3 Operators)
Projected Labor Savings Labor Reduction per Wash = 13 min = $3.35 Idle Time per Wash = 6 min * 3 = 18 min = $4.50 Total per Wash = $7.85 Total per Day = $7.85 * 5 = $39.25 Payback Period = 334 Workdays = 16 Months Salvage Value Not Considered, Likely Substantial
Labor Savings RobustnessCalculated Savings
are Intentionally Conservative
Using 6 Washes per Day or Idle Time Avoidance of 10 min Significantly Improves Expected Payback Period
Payback Period02468
1012141618
Conservative 6 WashesIdle 10 min
Other BenefitsAdded Washing CapacityLiberated Wash Station OperatorOne Year Warranty on WasherWasher Salvage ValueLess Consumables (Gloves, Rags)Less Material Handling
Equipment (Carts)Cleaner, More Orderly Facility
Potential DrawbacksFailure to utilize liberated
operators.If proposal assumptions do not
hold in practice, the projected labor savings are likely to change significantly.
If maintenance issues happen more frequently than expected (typically twice per year), the projected labor savings will not be realized.
RecommendationsIn the opinion of the investigating
team, the following steps should be pursued as soon as convenient:
Initiate Contact with Hotsy Request Delivery of Washer to Air Park for
Trials Verify the Cleaning Ability of the Washer Install the Washer if Cleaning Ability is
Satisfactory Run Trials through the Installed Washer Verify the Practicality of Proposal Assumptions Purchase the Washer if Practicality is Verified
DISCUSSIONQuestions & Comments