Improving Railroad Classification Terminal Performance Using Concepts of “Lean Railroading”

Jeremiah DirnbergerRailroad Engineering Program

University of Illinois Urbana-Champaign

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Problem Statement

Inadequate terminal capacity is a barrier to improved service reliability

Building new terminals and/or expanding existing terminals are the most costly alternatives

New methods are needed to harness as much capacity from the existing infrastructure

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Presentation Outline

1.0 – Define Lean Railroading

2.0 – The Terminal as a Production System

3.0 – Identifying and Understanding the Bottleneck

4.0 – A Quality of Sort Metric for Improved Terminal Management

5.0 – Implementing the Metric

6.0 – Conclusions

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1.0 – What is “Lean Railroading?”• The adaptation of proven production management

methods to the railroad environment– Lean– Theory of Constraints (TOC)– Statistical Process Control (SPC or six sigma)– Scheduled railroading is key

• Define value for the ultimate customer– “The ideal product for my customer is . . .”

• Then eliminate waste (any activity that does not add value)– Direct waste (“bad railroading”)– Variability (the root of all waste!)

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The Building BlocksImproved network

efficiency

Increased service reliabilityand value

Increased terminal capacity

Lean Theory of Constraints

Statistical Process Control

Variability reduction Eliminate directwaste

Bottleneckimportance

Factory Physics(the “science of manufacturing”)

Previous railroad reliability studies(FRA, AAR, MIT)

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Lean Railroading• Lean Railroading is just beginning

– GE Yard Solutions Group – CPR Yard Operations Performance Group– UP VP Continuous Improvement– BNSF Value Engineering Group– The CN Philosophy

• GE estimates dwell time reduction could result in 15-30% terminal capacity improvement

• CPR reports from March 2005-2006:– Average terminal dwell fell 8.7 hours– Average train speed increased 3.6 mph

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Implementing Lean RailroadingImplementation steps:

0. Eliminate direct waste: Take a fresh look at the terminal system, try to eliminate obvious sources of waste (Value Stream Mapping)

- Rework, car damage, unnecessary motion, yard engine failure, long setups, unnecessary information collection, etc.

1. Swap buffers: Decrease the time buffer by reducing idle time (continuous flow), increase the capacity buffer by improving bottleneck performance

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Implementing Lean Railroading2. Reduce variability:

a. Address problems in sorting, rework, car damage, down time and setups (apply SPC/”six sigma”)

b. Implement standardized work plansc. Work with network management to increase on-

time arrival of inbound trainsd. Level the production schedule in the yard and set

the network operating plan

3. Continuous improvement:“Once variability is significantly reduced, we can reduce the capacity buffer while continuing to identify and eliminate variability. Only at this point do we begin to make real gains in productivity.”

Spearman (2002) Factory Physics White Paper Series Part II

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2.0 – The Classification Terminal as a Production System

[The Union Pacific] is a “33,000 mile factory – with no roof.”Dick Davidson, 2003Chairman and former CEO

“This situation is analogous to a manager of an automobile assembly plant . . . In the railroad industry, the terminal superintendent is the plant manager and his function is to assemble inbound trains or parts of trains into completed outbound trains.”

Ferguson, 1980AAR No. R-412

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The Terminal as a Production System

Inbound trains

Methods/procedures

Information

People

Weather

Infrastructure

Equipment

Outbound trains

Services

Information

“Paperwork”

A classification terminal is a factory that makes connections in the form of trains

Enables use of proven production management techniques in the form of Lean Railroading

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Hump Yard LayoutClassification

tracks (The Bowl)

Hump &hump tower

Departure yard

Arrival yard

UP Centennial YardFt. Worth, TX

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3.0 – Identifying and Understanding the Bottleneck

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Identifying a Terminal’s BottleneckTr

ain ar

rival Idle

Inboun

d insp

ectio

n Idle

Bowl (i

dle)

Hump s

et-up

Hump

Pull-dow

n Idle

Idle

Power

onBad

orde

r set-

out

Total

cycle

time

Depart

ure

Inspec

tion &

air t

est

Work time (hrs)Idle time (hrs)

71%

29%

Idle (dwell) time (hrs)

Work time (hrs)

Courtesy of Logan (2006) TRB Presentation

Past studies and railroad management also identify the pull-down process as the bottleneck

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The Pull-Down ProcessThe pull-down process involves blocks of cars being pulled from the bowl and placed together to form outbound trains in the departure tracks

Car flow during pull-down

Hump yard with parallel receiving and departure yards

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Current Bottleneck Management ExampleAgincourt Yard (CPR) in Toronto uses the hump pusher engine to build trains when the hump would otherwise be idle

Build trains from both ends of the bowl

Class yard (bowl)

Hump

Departure yard

Receiving yard

Bottleneck capacity increased without any additional infrastructure!

2 jobs maxAdd 1 job when hump idleAvg. time in hump

mode = 52.40%

However, this approach doesn’t work in all yard designs

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Understanding the Pull-Down Process

Departure Yards

• Consists of two major activities:– Coupling– Pulling

• Two methods of making up trains:– Multiple pulls per engine– Single pull per engine

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Pull-down Cycle Time ComponentsQueue(Wait)

Transport(Pulling)

Start(Bowl)

End(DP Tracks)

Bowl(Coupling)

Yes

NoRework? Placement

(Uncouple)

Bowl time(estimated from PROYARD)

Transport time(Time studies)

Rework time(Time studies)

F (number of cars, joints, gap spacing,

discrepancies)

F (distance, speed, number of engines,

number switches thrown, number of cars,

interference)

F (standing order)

Previous GE study:The most significant factor of transport time is time spent throwing switches

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Why does rework occur?Factors:

1) “Cherry-picking” high priority cars2) Removing misrouted or mis-sorted

cars

Hypothesis: As bowl volume increases, the number of misroutes and mis-sorts also increases

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Number of misroutes vs. cars humpedBensenville Yard (CPR), 1/1/2005 to 4/10/2006

0

5

10

15

20

25

30

35

0 200 400 600 800 1000Cars humped per day

Num

ber o

f mis

rout

es p

er d

ay

Misroutes vs. bowl volume

Daily “average” bowl volume

Number of misroutes vs. bowl volumeBensenville Yard (CPR), 1/1/2005 to 4/10/2006

Number of misroutes

per day

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Improving Bottleneck ManagementAnalyze the immediate upstream process to find ways to decrease the workload of the bottleneck at all yards

Modify the humping process to make the job of the pull-down as easy as possible

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4.0 – A Quality of Sort Metric for Improved Terminal Management

“I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot express it in numbers, your knowledge is of a meager and unsatisfactory kind. . .”

Lord Kelvin

“You can’t manage what you can’t measure.”Unknown

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The Bowl Replay Program

Record all cars in the bowl at 0001 mm/dd/yyyy

Add cars humped into

the bowl

Remove cars pulled from

the bowlInclude trim and local/interchange

moves

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Bowl Replay Start 0001 11/15

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Bowl Replay 0222 11/15

25

Bowl Replay 0410 11/15

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The Quality of Sort Metric

Measures how well the cars are being sorted based on their impact on the bottleneck

Car level

Incorrect Sort Rating (ISR) Track level

Bowl level

Measured in number of cars, a lower ISR indicates fewer incorrectly sort cars

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Car Level ISR

Every car humped is rated against three components

Car ISR = RT + RG + BI

s.t. RT = 0 or αRG = 0 or βBI = 0 or µα + β + µ = 1

Where: RT is right car-right trackRG is right car-right groupBI is block integrity

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Track Level ISR ExampleThe track level reflects that pull-down process works by track

Track ISR = {∑all cars on track n Car ISR} x TF s.t. TF = δ or η

“Dirty” track → Penalize“Clean” track → Reward

Mechanical and re-hump tracks not multiplied by TF

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Occurrence of Dirty TracksClean and dirty tracks pulled

Bensenville Yard (CPR)

5

4 2

4

0

5

10

15

20

25

30

7-Mar-2006 21-Mar-2006 22-Mar-2006 23-Mar-2006Date of observation

Num

ber o

f tra

cks

Dirty

Clean

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The Impact of Dirty Tracks

Queue(Wait)

Transport(Pulling)

Start(Bowl)

End(DP Tracks)

Bowl(Coupling)

Yes

NoRework? Placement

(Uncouple)

(3 crews) x (7.25 hours/shift) x (60 min/hour) x (85%) = 1109.25 min available

Bowl, transport time and setup = 90 min → 12.325 pulls per shift

Average rework of dirty tracks = 25 min → 115 min

11 tracks to be pulled: 8 clean, 3 dirtyTotal time = 1065 min

11 tracks to be pulled: 11 cleanTotal time = 990 min

Fixing dirty tracks also creates the potential for more interference among pull-down engines

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Bowl Level ISR

Reflects overall performance of hump controller in maintaining a “clean” bowl

Bowl ISR = ∑for all tracks except “special” Track ISR

Hypothesis: As bowl volume increases, bowl ISR will increase

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The Bowl Replay Program

ISR Values:- Right Track, α = 0.25- Right Group, β = 0.25- Block Integrity, µ = 0.50- TF “Clean” track, δ = 0.50- TF “Dirty” track, η = S – B where S=number of separations and B = number of blocks

Removed when car pulled from bowl

Trim moves also reflected in program with movement penalty built in

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Bowl ISR vs. Bowl Volume

Average ISR vs. bowl volume for Alyth Yard, Sept. 13 to 17, 2005

ISR = 0.0021(BV)2 - 1.8156(BV) + 439.14

0

20

40

60

80

100

120

350 400 450 500 550 600 650BV = Bowl volume (number of cars)

Ave

rage

ISR

(num

ber o

f car

s)

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5.0 – Implementing the Metric Using SPCAlyth Yard X-bar ISRSeptember 13, 2005

0102030405060708090

0:30

2:30

4:30

6:30

8:30

10:30

12:30

14:30

16:30

18:30

20:30

22:30

Time (+15 min)

ISR

UCL = 54.76

Sample size, n=5

Use SPC to track ISR and identify root causes of an excessively dirty bowl or tracks

Process is outside of upper control limit

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Implementing the Metric –Potential Optimization Framework

Min ISR

s.t. Car Length (Track) < Remain ∑ Tracks Chosen = 1Mechanical tracks = 0

ISR = Right Car-Right Track + Block Integrity(Based on the current state of the group or bowl)

Decision support systems can be designed based on the Quality of Sort metric

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Improved Bottleneck Management

• The hump is not the constraint on the system– Correct misroutes and mis-sorts when they occur– Consider the benefits of re-humping– Management should emphasize quality in addition

to quantity

• Better coordination of the pull-down crews– Dedicated pull-down yardmaster– Standardized work, training, remote switch

machines

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6.0 – Conclusions

• Like many production systems, terminals focus too much on quantity and not enough on quality

• The ISR should be used in a yard management system to add a needed quality component to terminal performance management

• This work provides an illustration of the potential of Lean Railroading

• Lean can be applied throughout the railroad system

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Railroad Support

• CN: Funding, access to network operations personnel, yard site visits (Champaign, Toronto), hump data and yard simulation models

• CPR: Sponsored site visits and observations (Calgary, Toronto, Chicago), access to network operations personnel, TYES and PROYARD data, research and program feedback from YOP group and yard personnel, a job after graduation

Research Fellowship

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Railroad Support

• UP: Roseville yard site visit and program feedback

• BNSF: Denver yard background site visit

• NS: Decatur yard background site visit

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• UIUC: -Dr. Chris Barkan (Advisor)-Darwin Schafer, Justin Wood, Ahsan Alvi(Undergrad Assistants)-Rapik Saat (fellow Graduate Assistant)

• CPR: -Jeff Adams and the entire YOP Group-The Bensenville Yard Team-The Alyth Yard Team-The Agincourt Yard Team

• CN: -Mack Barker, Mike Meleskie-The MacMillian Yard Team-Merle Metz at Champaign Yard

• Prescott Logan of GE Yard Solutions

Acknowledgements