RESTORING ONE-PIECE FLOW TO LINCOLN INDUSTRIES Stephen Hassler, Jeffrey

TroesterUniversity of Nebraska - Lincoln

Department of Industrial & Management Systems Engineering

ContributorsHotsy Equipment Co. (NE)

Roy Gage – Sales Representative Dennis Klingemann – Sales Representative

Lincoln Industries (NE) Bill Hancock – Area Leader, Fabrication Eric Jacobs – Development Engineer

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 Problem

By 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 Objective

It 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.

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.

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.

STUDY DETAILSAnalysis Method & Findings

Four Step Analysis MethodUnderstand Problem and Magnitude

Visual Aids, Quality Inspection, Time StudiesDevelop Alternatives

Seek Expert Opinions, Creative BrainstormingVerify Feasibility of Alternatives

Examine Attributes and Costs, Design Experiments

Evaluate 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

DEBURR

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 MACHINE

CHIPS

CARTS

WASH

BEND MACHINE

UNLOADING BENDER

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.

Other BenefitsAdded Washing CapacityLiberated Wash Station OperatorOne Year Warranty on WasherLess Consumables (Gloves, Rags)Less Material Handling

Equipment (Carts)Cleaner, More Orderly Facility

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

16

1312

Conservative 6 WashesIdle 10 min

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

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 sKey Observations

Excessive Idle Time Frequently Congested Workstation Operator Sets Operation Pace Potentially the Bottleneck Operation

Develop AlternativesSeek Expert Opinion – Idea List

Power Washing Cabinet Power Washing Conveyor System Laser Cutting (No Chips) 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 AlternativesALTERNATIVE FEASIBILITY

DETERMINATIONPower Washing Cabinet FeasiblePower Washing Conveyor System

Infeasible – Poor Cleaning

Laser Cutting Infeasible – CostWater 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 CleaningEvaluate Alternatives

Economic 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

DescriptionPower Wash Cabinet Suggested

Settings 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.SAW

DEBURR

CARTS

BEND

WASH

WASH

≈ 10 FT

Proposal – Install Hotsy Model 7663Purchase Cost

$10, 650Tube Fixtures (5)

$1,250Consumables

$1,200 / YearTOTAL – YEAR 1

$13,100

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.

VACUUM EXPERIMEN

T

“More Value with Less Work”– Philosophy of Lean

Manufacturing

Image Sources: www.adventureinmetals.com, www.franeklaser.com, www.hotsy.com, www.lincolnchrome.com, www.lincolnindustries.com