Slide1x

SMU Senior Design Project: Southwest Airlines

Spring 2010

EMIS 4395-001

May 2010

2

Team On-Time Performance

• Stacy Moskowitz

• Brandon Cabello

• Courtney Guenard

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Agenda

• What makes them happy?

• Southwest: The Big Picture

• Is your line late?

• Say ‘No’ to late airports!

• Recommendations

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WHAT MAKES THEM HAPPY?

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We partnered with Southwest Airlines optimization group to tackle on-time performance

• Southwest uses a flight schedule to indicate a whole day’s worth of

flying by line

• They wanted our assistance to improve their forecast of the on-time

performance of entire scheduled line

– Historically, on-time performance has been measured by a leg-by-leg

basis

– Southwest provided our group with historical turn and block time

data for all flights from January 2009

Turn time

DFWORD

Turn time

LAX

Sample: Line Schedule

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SOUTHWEST: THE BIG PICTURE

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Today, Southwest operates 537 aircrafts between 68 cities

Image Source: Southwest Airline Systems Map 2008

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Based on our data, here we show the top 10 airports by departure

0

1000

2000

3000

4000

5000

6000

7000

8000

6707

55565284

437737923702

3393338832973190

Southwest’s Top Ten Airports – Number of Departures

Orlando

Southwest’s Top Ten Airports – Number of Departures

DenverLos An-

gelesOakland

Dallas Love

HoustonHobby

Las Ve-gas

ChicagoMidway

PhoenixBalti-moreWash.

Source: Jan 09 Flight Data; Southwest AirlinesAnalysis by: B Cabello, S Moskowitz, C Guenard

On-time performance at these airports is crucial from a customer service and cost perspective

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Next, we segmented the data into legs and lines

City 1

City 2

City 3

City 4

City 5

City 6

Line OAK FLL AUS OAK

Line LAX BUF BWI SAT ELP

Line SJC RDU BNA ONT SJC LAS

Line HOU OAK SEA MCI MCO

Line BWI SAN LAS MDW ALB

Line LAX MCO PHX SEA

Line HOU RDU BNA LAS CMH

Southwest’s Flights OverviewSouthwest’s overall count of lines and legs

LineLeg0

10000

20000

30000

40000

50000

60000

70000

80000

90000

15718

78599

These two segments were analyzed for on-time performance

Start End

Leg OAK FLL

Leg LAX BUF

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As a whole, 56% of Southwest’s flights arrive on-time to their destination

Late34363

On-time 44236

Southwest’s On-time Performance (by Leg)

Southwest’s overall count of on-time and late flights

Late44%

On-time56%

Southwest’s On-time Performance (by Leg)

Southwest’s overall on-time and late flights as a %

Source: Jan 09 Flight Data; Southwest AirlinesAnalysis by: B Cabello, S Moskowitz, C Guenard

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Here we measured lateness by line (full day’s worth of flying)

Southwest’s Lateness CountSouthwest’s overall count of on-time and late flights

Southwest’s Lateness %Southwest’s overall on-time and late flights a %

Line0

2000

4000

6000

8000

10000

12000

14000

16000

18000

On-time12496

Late3222

Line0%

20%

40%

60%

80%

100%

120%

On-time 80%

Late20%

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After researching lateness, we also measured a lines ability to recover

Recovered

10%

Did Not90%

Southwest’s Recovery PerformanceSouthwest’s overall recovery % for all lines

Table of Late Lines which Recovered (not all shown)

Line OAK FLL AUS OAK

Line LAX BUF BWI SAT ELP

Line SJC RDU BNA ONT SJC LAS

Line HOU OAK SEA MCI MCO

Line BWI SAN LAS MDW ALB

Line LAX MCO PHX SEA

Line HOU RDU BNA LAS CMH

Line AUS SJC PHX MHT

Line SFO FLL MCI LAX

Line PHX HOU SAT MCO

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IS YOUR LINE LATE?

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Our research shows over 3200 lines experience at least one-late leg

Southwest’s Lateness CountSouthwest’s overall count of on-time and late lines

Line0

2000

4000

6000

8000

10000

12000

14000

16000

18000

On-time 12496

Late3222

This analysis led us to explore our next area of investigation; airports

Table of Late Lines which Recovered (not all shown)

Line SMF BWI BNA

Line OAK MDW BWI STL DAL

Line PHX MDW PIT TPA

Line FLL ABQ MCO MSY DAL BHM

Line SMF PHX MHT TPA FLL

Line SEA LAS MCI IND

Line SJC LAS BWI ISP PBI

Line BWI ORF MDW

Line SMF MCO BWI

Line SJC SFO LAX MCI

= delayed departure = on-time arrival resulting in recovery

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SAY ‘NO’ TO LATE AIRPORTS

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We began this study by counting the number of on-time and late arrivals by airport

Count of Late/On-time

Arrivals by Airport

BUF

MDW

PDX

DEN BUR

AMA

HRL

0

1000

2000

3000

4000

5000

6000on-time count

late count

Probability Late Flights by

Airport

BUF

MDW

PDX

DEN BUR

AMA

HRL

0%

10%

20%

30%

40%

50%

60%

70%

80%

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Statistical analysis of lateness by airport shows a leftward skew

Airport Lateness Frequency

Histogram

0-36% 36-42%

42-47%

47-68%

0

5

10

15

20

25

30

35

40

Airport Lateness Frequency Box

Plot

January-090%

5%

10%

15%

20%

25%

30%

35%

40%

45%

50%

average

outliers outliers

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This chart shows the 20 best and worst airports

BUFDTWCM

H

MDW

BWI

FLL

PDXSLCPIT

DENDALPHX

BURJA

NTU

LAM

AM

AFLB

BHRL

CRP0%

10%

20%

30%

40%

50%

60%

70%

80%

68%65%

61%

56%55%55%51%51%51%50%49%48%

32%31%29%28%

23%22%22%

13%

Southwest’s 20 Best and Worst Airports – Lateness Fre-quency

Airports listed in red are one of Southwest’s Top 10 Airports (by volume)

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RECOMMENDATIONS

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To improve Southwest flight schedules, we would like to make the following recommendations

Research Category Recap Recommendations

Line Analysis

• 20% of SW lines are late

• Line lateness led us to

explore trouble some

airports

• Although solving for

airport lateness is

important, a lines ability to

recover is valuable

• Further analysis on

Southwest’s best and

worst airports would lend

address turn time and

overall line performance;

• Recovery airports may

hold the key to improving

turn-time at

underperforming airports

Airport Analysis

• Airport lateness ranged

from 13% - 68%

• A histogram showed us

the outlier airports; with 5

top airports included in the

high side