Transportation Systems Analysis Model And Very Light Jet Demand

-Automobiles -Commercial Air -New Mode or Vehicle

Airports IPT - JPDO

November 15, 2005

Transportation Systems Analysis Model (TSAM)

Jeff Viken (757-864-2875) [email protected]

Stuart Cooke

NASA Langley Research Center

Antonio Trani (540-231-4418) Hojong Baik Nick Hinze Senanu Ashiabor Howard Swingle Anand Seshadri Krishna Murthy

Virginia Tech University

Sam Dollyhigh John Callery Jeremy Smith

Swales Aerospace

Attributes of the Transportation Systems Analysis Model

• Computes

national

demand for long distance travel • Aggregates demand from

3,091 county

level projections • Socio-economic based (5 different income levels) • Models preferences for purpose of travel: Personal or Business • Models all legs of trip from doorstep to doorstep • Future projections can be made to 2025 • Multi-modal in scope • Uses accepted transportation analysis methods • Aerospace technology sensitive (demand related to trip cost and time) • Demand can be based upon supply/capacity relationships • Demand studies an be applied to full range of NASA and FAA aviation projects • Systems studies can be made to model a complete national transportation system (Commercial Airlines in the NAS, SATS)

Premise that Defines Importance of TSAM to Users

Gains in capacity in the NAS and mobility to the traveler are credible only if: Demand is predicted correctly….

– – – – –

Numbers of travelers Location of travelers Trip cost Total trip time Safety, perceptions, etc TSAM models travel statistics from:

–

population

–

income

–

purpose at the county level, and not from a regression of trend variables

Transportation Systems Analysis Model

Aerospace Technology

Trip Demand Generation

Given

: Socio-economic characteristics for each county (for all states)

Predict

: a) Number of trips produced per household/year for various income levels b) Trip attractiveness to a county

Use:

Trip rate tables

16 14 12 10 2 0 8 6 4 Business Non-Business < 30k 30k to 60k 60k to 100k 100k to 150k Annual Household Income ($) > 150k

Household Income Changes (2000-2025)

Woods and Poole Data Implemented in the Transportation Systems Analysis Model

Changes in the U.S. Population (Years 2000 to 2025)

Woods and Poole Demographic Data Implemented in the Transportation Systems Analysis Model

Trip Distribution Analysis

Given

: Trips produced from and attracted to each county

Predict

: a) Number of person-trips from each origin to every destination (county to county)

Use:

Gravity Model T ij = P i A j F ij K ij n  j1= A j F ij K ij

Trip Distribution (From)

Trip Distribution (To)

Selecting a Mode of Travel

Auto New or Improved Mode Commercial Aviation

• • • • • • •

Factors considered in selecting a mode: Travel time Travel cost Value of time Route convenience Trip type Reliability of service Frequency of service

Route1 Route2... Route n Includes Airport Choice

Multiple Route Mode Choice

Mode of Transportation Auto Airline (Coach) Airline (Business) SATS Distance (miles) 2154 2690 2690 1920 Cost ($) 1140 630 1830 2940 Time (hrs) 34.4

16.4

16.4

10.4

Mode Choice - Auto

Mode Choice – Commercial Air

Mode Choice – SATS / Very Light Jets

Airport Demand - Commercial

Airport Demand - SATS / Very Light Jets

Description of the Very Light Jet Aircraft

• Pressurized aircraft • Four revenue seats • 365 mph cruise speed • Certified to fly into known icing conditions • 1,100 nm range • Cost per passenger-mile ($1.75 nominal based on life-cycle cost analysis) • 3415 public airports (> 3,000 ft. paved runways) • Low Landing Minima capability provided to all airports using SATS LLM hardware (WAAS aided) • Airport Design Group = A-I • Wake Vortex Classification = Small

4,800 Very Light Jets in

7,000

Service by 2016

High Production Rate 6,000 Moderate Production Rate Low Production Rate 5,000 4,000 3,000 2,000 1,000 0 2007 2010 2013 Year 2016 2019 2022

On-demand Cost Model (@ 1.75 passenger-mile) using VLJ Aircraft

VLJ Traffic in 2014 with OEP Airports

VLJ Traffic in 2025 with OEP Airports

Spatial Distribution of VLJ Operations (2014)

Top 30 Airports (2014) with OEP Airports

Scenario: Year 2014 with OEP Airports Mc Carran Intl. (LAS) Midway (MDW) Love Field (DAL) Fulton Co. (FTY) Dekalb-Peachtree (PDK) Fort Lauderdale Exec. (FXE) Salt Lake City Intl. (SLC) Reagan National (DCA) Farmingdale-Republic (FRG) Teterboro (TEB) Stinson Municipal (SSF) Montgomery Co. MD (GAI) Centennial (APA) Fort Worth Meacham (FTW) Sugar Land Reg. (SGR) St. Louis Downtown (CPS) North Las Vegas (VGT) Oakland Co. MI (PTK) N. Mineta San Jose (SJC) Manassas Regional (HEF) Reno-Tahoe Intl. (RNO) Van Nuys (VNY) William P. Hobby (HOU) Fresno-Yosemite (FAT) Orlando Executive (ORL) Essex Co. NJ (CDW) L.G. Hanscom Field (BED) Gwinnett Co. (LZU) Oakland-Troy (7D2) Albuquerque Intl. (ABQ) Westchester Co. (HPN) Arrivals Departures 0 50 100 150 200 Daily Flights 250 300 350 400

Top 30 Airports (2014) No OEP Airports

Scenario: Year 2014 no OEP Airports North Las Vegas (VGT) Love Field (DAL) Fort Lauderdale Exec. (FXE) Fulton Co. (FTY) Dekalb-Peachtree (PDK) San Antonio Intl. (SAT) Oakland Co. MI (PTK) St. Lake City Muni. (U42) Van Nuys (VNY) Farmingdale-Republic (FRG) Dupage (DPA) Teterboro (TEB) William P. Hobby (HOU) Opa Locka (OPF) Gwinnett Co. (LZU) Albuquerque Intl. (ABQ) Palwaukee Muni. (PWK) Fort Worth Meacham (FTW) St. Louis Downtown (CPS) Sugar Land Reg. (SGR) Montgomery Co. MD (GAI) Boise Air Terminal (BOI) Morristown Muni. (MMU) Essex Co. NJ (CDW) Reno-Stead (4SD) Orlando Executive (ORL) Willow Run (YIP) Centennial (APA) Fresno-Yosemite (FAT) Boulder City Muni. (61B) L.G. Hanscom Field (BED) Westchester Co. (HPN) 0 100 200 300 Daily Flights 400 Arrivals Departures 500

Top 30 Airports (2025) with OEP Airports

Scenario: Year 2025 with OEP Airports Mc Carran Intl. (LAS) Love Field (DAL) Midway (MDW) Fort Lauderdale Exec. (FXE) Fulton Co. (FTY) Dekalb-Peachtree (PDK) Stinson Municipal (SSF) Reagan National (DCA) Salt Lake City Intl. (SLC) Sugar Land Reg. (SGR) North Las Vegas (VGT) Fort Worth Meacham (FTW) William P. Hobby (HOU) Teterboro (TEB) Farmingdale-Republic (FRG) Albuquerque Intl. (ABQ) Reno-Tahoe Intl. (RNO) Boise Air Terminal (BOI) L.G. Hanscom Field (BED) Montgomery Co. MD (GAI) Miami Intl. (MIA) Van Nuys (VNY) Oakland Co. MI (PTK) Centennial (APA) N. Mineta San Jose (SJC) Kansas City Downtown (MKC) Orlando Executive (ORL) St. Petersburg (PIE) St. Louis Downtown (CPS) Gwinnett Co. (LZU) Oakland-Troy (7D2) Arrivals Departures 0 100 200 300 400 Daily Flights 500 600 700

Top 30 Airports (2025) No OEP Airports

Scenario: Year 2025, No OEP Airports North Las Vegas (VGT) Love Field (DAL) Fulton Co. (FTY) Fort Lauderdale Exec. (FXE) Dekalb-Peachtree (PDK) San Antonio Intl. (SAT) Oakland Co. MI (PTK) St. Lake City Muni. (U42) William P. Hobby (HOU) Fort Worth Meacham (FTW) Sugar Land Reg. (SGR) Teterboro (TEB) Gwinnett Co. (LZU) Van Nuys (VNY) Opa Locka (OPF) Dupage (DPA) Centennial (APA) Palwaukee Muni. (PWK) Orlando Executive (ORL) Westchester Co. (HPN) Albuquerque Intl. (ABQ) N. Mineta San Jose (SJC) Farmingdale-Republic (FRG) Montgomery Co. MD (GAI) Boeing Filed (BFI) Boise Air Terminal (BOI) Reno-Stead (4SD) Fresno-Yosemite (FAT) Morristown Muni. (MMU) Flying Cloud (FCM) St. Petersburg (PIE) 0 100 200 300 400 Daily Flights 500 600 Arrivals Departures 700 800

Top 30 Airports (2014) No OEP Airports

Airport Operations - 2014 - no OEP North Las Vegas (VGT) Love Field (DAL) Fort Lauderdale Exec. (FXE) Fulton Co. (FTY) Dekalb-Peachtree (PDK) San Antonio Intl. (SAT) Oakland Co. MI (PTK) St. Lake City Muni. (U42) Van Nuys (VNY) Farmingdale-Republic (FRG) Dupage (DPA) Teterboro (TEB) William P. Hobby (HOU) Opa Locka (OPF) Gwinnett Co. (LZU) Albuquerque Intl. (ABQ) Palwaukee Muni. (PWK) Fort Worth Meacham (FTW) St. Louis Downtown (CPS) Sugar Land Reg. (SGR) Montgomery Co. MD (GAI) Boise Air Terminal (BOI) Morristown Muni. (MMU) Essex Co. NJ (CDW) Reno-Stead (4SD) Orlando Executive (ORL) Willow Run (YIP) Centennial (APA) Fresno-Yosemite (FAT) Boulder City Muni. (61B) L.G. Hanscom Field (BED) Westchester Co. (HPN)

0 2004 Local 2004 Itinerant 2014 Local 2014 Itinerant 2014 SATS / VLJ 500 1000

Daily Operations

1500 2000

Top 30 Airports (2014) With OEP Airports

Airport Operations - 2014 - With OEP Mc Carran Intl. (LAS) - OEP Midway (MDW) - OEP Love Field (DAL) Fulton Co. (FTY) Dekalb-Peachtree (PDK) Fort Lauderdale Exec. (FXE) Salt Lake City Intl. (SLC) - OEP Reagan National (DCA) - OEP Farmingdale-Republic (FRG) Teterboro (TEB) Stinson Municipal (SSF) Montgomery Co. MD (GAI) Centennial (APA) Fort Worth Meacham (FTW) Sugar Land Reg. (SGR) St. Louis Downtown (CPS) North Las Vegas (VGT) Oakland Co. MI (PTK) N. Mineta San Jose (SJC) Manassas Regional (HEF) Reno-Tahoe Intl. (RNO) Van Nuys (VNY) William P. Hobby (HOU) Fresno-Yosemite (FAT) Orlando Executive (ORL) Essex Co. NJ (CDW) L.G. Hanscom Field (BED) Gwinnett Co. (LZU) Oakland-Troy (7D2) Albuquerque Intl. (ABQ) Westchester Co. (HPN)

0 500 1000

Daily Operations

1500 2004 Local 2004 Itinerant 2014 Local 2014 Itinerant 2014 SATS / VLJ 2000

Top 30 Airports (2025) No OEP Airports

Airport Operations - 2025 - no OEP North Las Vegas (VGT) Love Field (DAL) Fulton Co. (FTY) Fort Lauderdale Exec. (FXE) Dekalb-Peachtree (PDK) San Antonio Intl. (SAT) Oakland Co. MI (PTK) St. Lake City Muni. (U42) William P. Hobby (HOU) Fort Worth Meacham (FTW) Sugar Land Reg. (SGR) Teterboro (TEB) Gwinnett Co. (LZU) Van Nuys (VNY) Opa Locka (OPF) Dupage (DPA) Centennial (APA) Palwaukee Muni. (PWK) Orlando Executive (ORL) Westchester Co. (HPN) Albuquerque Intl. (ABQ) N. Mineta San Jose (SJC) Farmingdale-Republic (FRG) Montgomery Co. MD (GAI) Boeing Filed (BFI) Boise Air Terminal (BOI) Reno-Stead (4SD) Fresno-Yosemite (FAT) Morristown Muni. (MMU) Flying Cloud (FCM) St. Petersburg (PIE)

0 500 1000 1500

Daily Operations

2004 Local 2004 Itinerant 2025 Local 2025 Itinerant 2000 2500

Top 30 Airports (2025) With OEP Airports

Airport Operations - 2025 - with OEP Mc Carran Intl. (LAS) - OEP Love Field (DAL) Midway (MDW) - OEP Fort Lauderdale Exec. (FXE) Fulton Co. (FTY) Dekalb-Peachtree (PDK) Stinson Municipal (SSF) Reagan National (DCA) - OEP Salt Lake City Intl. (SLC) - OEP Sugar Land Reg. (SGR) North Las Vegas (VGT) Fort Worth Meacham (FTW) William P. Hobby (HOU) Teterboro (TEB) Farmingdale-Republic (FRG) Albuquerque Intl. (ABQ) Reno-Tahoe Intl. (RNO) Boise Air Terminal (BOI) L.G. Hanscom Field (BED) Montgomery Co. MD (GAI) Miami Intl. (MIA) - OEP Van Nuys (VNY) Oakland Co. MI (PTK) Centennial (APA) N. Mineta San Jose (SJC) Kansas City Downtown (MKC) Orlando Executive (ORL) St. Petersburg (PIE) St. Louis Downtown (CPS) Gwinnett Co. (LZU) Oakland-Troy (7D2)

0 500 2004 Local 2004 Itinerant 2025 Local 2025 Itinerant 2025 1000 1500 2000

Daily Operations

2500 3000 3500

Impact of VLJ Operations at Non-Towered Airports

Fresno-Chandler (FCH) Provo Municipal (PVU) Palm Beach Co. (LNA) Boulder City Muni. (61B) Carson City (CXP) Leesburg Executive (JYO) Vandenberg (VDF) Denton Municipal (DTO) Knoxville Downtown (DKX) Lee Gilmer Memorial (GVL) Madera Municipal (MAE) Tipton - Maryland (FME) Herlong - Jacksonville (HEG) Jean - Las Vegas (OL7) Millard-Omaha (MLE) Schaumburg Regional (O6C) Cincinnati-Blue Ash (ISZ) Oakland/Troy (7D2) Montgomery County (GAI) VLJ Operations Itinerant Commuter/Air Taxi Itinerant General Aviation Local General Aviation 0 100 200 300 400 Daily Operations 500 600 700

2014 VLJ Air-Taxi NAS Impacts

Airspace Impacts (Year 2014)

ZNY ZTL ZOB ZDC ZID ZAU ZMA ZJX ZME ZLA ZHU ZMP ZKC ZFW ZBW ZDV ZAB ZOA ZLC ZSE 0 2000 4000 6000 8000 ETMS Traffic (2004) FAA Center Projections (2014) VLJ Traffic (2014) 10000

Daily Aircraft Operations (IFR)

12000 14000

NAS Daily Flights

Baseline NAS: 2004 ETMS Projections: 2014 - NAS Flights + VLJ 2025 - NAS Flights + VLJ Baseline and Projected NAS Daily Traffic

140000 120000 100000 80000 60000 40000 20000 0 57,628 13133 36769 2004 97,969 18576 1.70

16512 53902 1.38

127,421 25800 2.21

21098 69647 1.76

SATS / VLJ Military Freight G/A Commercial / Air Taxi / Commuter 2014

Ye ar of Analys is

2025 / 2X

Historical Travel Growth

FAA Terminal Area Forecast (TAF) • Years 1981 to 2000 – Enplanements - 142% increase – Air Carrier Itinerant Operations - 57% increase – GA Itinerant Operations - 5% decrease !

– Total Itinerant Operations - 18.6% increase Note: GA and Total Itinerant Operations include GA VFR flights

FAA Terminal Area Forecast (TAF)

• TAF reports Itinerant Operations in 4 categories – Air Carrier – Air-Taxi and Commuter – Military – General Aviation • Air Carrier and Air-Taxi/Commuter are the major drivers of Operations in NAS and OEP airports • General Aviation operations are approximately 2/3 VFR flights

Projected Travel Growth

FAA Terminal Area Forecast (TAF) Note the different growth ratios between demand and operations

TAF Summary

0.7

0.3

0.2

0.1

0 0.6

0.5

0.4

2014

Scheduled Enplanments AC ops AT & Comm ops GA ops Total Itinerant ops Total ops inc local

Year

Projected Travel Growth

FAA Terminal Area Forecast (TAF) Base Year 2004

Enplanement Ratio to Base Year 1.2X

1.4X

2X 3X Year Predicted by TAF 2009 2014 2028 2043 Air-Carrier Ops Ratio 1.13

1.26

1.68

2.28

Air-Taxi / Commuter Ops Ratio 1.11

1.2

1.5

1.9

Total Itinerant Ops Ratio 1.07

1.14

1.34

1.61

Note: Data past 2020 taken from 2019-2020 growth rate Total Itinerant Ops includes GA VFR flights FAA predicts average aircraft size to increase which does not reflect recent growth in Regional Jet flights

Projected Travel Growth

FAA Terminal Area Forecast (TAF) Airport enplanement and operations growth highly dependent on the airport set examined

Growth From 2004 to 2014 35 OEP Airports All TAF Airports Growth in Enplanements 41.0% 40.0% Growth in Operations 29.4% 13.6%

Transportation Systems Analysis Model (TSAM) Demand

• TSAM can make future projections (to 2030) for the following: – Commercial airline demand and operations – Legacy General Aviation operations – SATS / VLJ / Air-Taxi both demand and operations (Emergent travel mode) – International Commercial Airline demand and operations (currently in development) – Cargo demand and operations (proposed future development)

TSAM comparison with Domestic Enplanement Data

2004 TSAM:

Business trips 86.7M

Personal trips: 154.0M

Total Commercial Airline Trips: 240.7M

How does this relate to enplanements?

Assumption: ~36% of trips have connection Each person trip has 2 trips - Depart and Return

TSAM Commercial Enplanements: 654.7M

ATA/FAA Reported Enplanements: 635.5M (3% difference)

•

TSAM Commercial Airline Demand Projections

Relative to base year 2004

Year

2009 2014 2025 2047

Growth Ratio

1.4

1.6

2.0

3.0

* * Based on growth rate 2024 to 2025

TSAM Demand is a Function of Ticket Cost to Traveler FAA Fare Yield Projections

Year Current $ FY 2004 $ 1999 13.54

15.32

2000 2001 2002 2003 2004 2005 2006 2007 14.03

13.53

11.88

11.73

11.46

11.11

11.15

11.25

15.38

14.38

12.45

12.00

11.46

10.81

10.62

10.47

2008 2009 2010 2011 2012 2013 2014 2015 2016 11.39

11.53

11.65

11.79

11.95

12.10

12.25

12.39

12.54

10.35

10.23

10.10

9.97

9.86

9.74

9.62

9.50

9.37

Yearly Change 0.39% -6.50% -13.42% -3.61% -4.50% -5.67% -1.76% -1.41% -1.15% -1.16% -1.27% -1.29% -1.10% -1.22% -1.23% -1.25% -1.37% From 2000 -6.50% -19.05% -21.98% -25.49% -29.71% -30.95% -31.92% -32.70% -33.49% -34.33% -35.18% -35.89% -36.67% -37.45% -38.23% -39.08% From 2004 -5.67% -7.33% -8.64% -9.69% -10.73% -11.87% -13.00% -13.96% -15.01% -16.06% -17.10% -18.24%

FAA Aerospace Forecasts, 2005-2016, Table 14, Air Carrier Fare Yields

Fare Yield Scenarios Analyzed

Fare Yield Scenario 2005 (January)

FAA Forecast • Maintain low fares Fares return to 2000 levels Oil greatly exceeds CPI -30.0% -30.0% -30.0% -30.0%

2014

-37.8% -25.0% 0.0% +10.0%

2025

-55.8% -25.0% 0.0% +25.0%

TSAM - Sensitivity of Air Travel to Fare Yields 500 400 300 200 100 0 1000 900 800 700 600 2004 2014 Year 2025

Non-Business Fare Yields: 1/.622/.542

FAA TAF Non-Business Fare Yields: 1/.78/.65 RTM Non-Business Fare Yields: 1/1/1 Business Fare Yields: 1/.622/.542 FAA TAF Business Fare Yields: 1/.78/.65 RTM Business Fare Yields: 1/1/1

TSAM comparisons with TAF

2014

TSAM: Fare Yield Scenario Fare Yield Reduction Business Person Trips Non-Business Person Trips Total Person Trips Growth From 2004 FAA Forecast Maintain Low Fares Return to 2000 levels Oil Prices Exceed CPI

-37.80% 123.2M

290.7M

413.9M

72% -25% 119.8M

243.7M

363.5M

51% 0% 116M 197.6M

313.6M

30% 10% 114.6M

181.3M

295.9M

23%

Total Enplanements

1,125.8M

988.7

853 804.8

FAA Projected Enplanements: 879.2M

Future Airline Schedules to Meet Demand Projections

• Future flight schedules are grown from current commercial schedules using the Fratar algorithm • Airplanes are assumed to have an average 70% load factor • Increased passenger demand between airports can be met with a combination of increased flight frequency

and

larger aircraft • Research by Airbus 1 (

next slide

) indicates that airlines will satisfy increased demand by adding the following service (flights refer to

all

airlines combined): – Total round trip flights <= 6 - Increase frequency of flights between airports – Total round trip flights > 60 - Increase capacity (size) of aircraft – Total round trip flights in between: Use a combination of increased frequency and increased capacity.

1) http://www.airbus.com/pdf/media/GMF2004_demand_passenger.pdf

Direct Flights

• • • • • • As demand increases between city pairs in the future, we model airlines introducing direct flights where non existed previously We model this by introducing 2 direct flights (each way) per day when passenger demand exceeds 25k trips per year Add 1 morning and 1 evening direct flight each way Remove shortest connecting route flights from future schedule (only flights of 2 legs considered) 2 direct flights replace 4 connecting flights The base schedule has not been changed.

ATL Departures and Arrivals X2 with Direct Flights and Consolidation of Operations to Larger Aircraft

80 70 60 50 40 30 20 -50 -60 -70 -80 10 0 -10 0 4 -20 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72 76 80 84 88 92 96 -30 -40

Epoch (15 minutes)

2004 Dep 2004 Arr X2 Dep X2 Arr Direct+Cons Dep Direct+Cons Arr

ORD Departures and Arrivals X2 with Direct Flights and Consolidation of Operations to Larger Aircraft

80 70 60 50 40 30 20 -50 -60 -70 -80 10 0 -10 0 -20 4 -30 -40 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72 76 80 84 88 92 96

Epoch (15 minutes)

2004 Dep 2004 Arr X2 Dep X2 Arr Direct+Cons Dep Direct+Cons Arr

Commercial Operations Based on 2X Passenger Demand

System Total Flights Flight Growth Ratio 2004 2X Direct Flights Direct Flights+ Larger Aircraft 35,605 72,737 68,671 63,963 2.04X

1.93X

1.80X

ATL Flight Growth Ratio 2,620 6,465 5,512 2.47X

2.10X

4,704 1.80X

ORD Flight Growth Ratio 2,773 5,936 5,505 2.14X

1.99X

4,808 1.73X

Note: Based on FAA Fare Yield Projections

Commercial Operations Based on 3X Passenger Demand

System Total Flights Flight Growth Ratio 2004 3X Direct Flights Direct Flights+ Larger Aircraft 35,605 108,955 100,811 82,156 3.06X

2.83X

2.31X

ATL Flight Growth Ratio 2,620 10,162 8,318 3.88X

3.17X

5,596 2.14X

ORD Flight Growth Ratio 2,773 8,577 7,773 3.09X

2.80X

5,687 2.05X

Note: Based on FAA Fare Yield Projections

Traffic Assignment

•

BADA Model

•

Aircraft performance

•

Fuel

• •

4D Trajectories FAA airspace sectors

TSAM - Concluding Remarks

• • • • • • • TSAM is a unique model that projects the national demand for travel from socio-economic and population characteristics by county TSAM can compute the demand for a completely new mode of travel diverted from existing travel modes Near term goal is to be able to build completely new and arbitrary Commercial Airline networks in the NAS from county demand A new point-to-point transportation network (SATS, etc) can be built from county demand Current and future International Airline traffic in the NAS can be modeled Can be used to conduct noise and emission studies, both on a regional and national level, with current and proposed vehicles and transportation networks.

Can be used to evaluate the demand for a given technology investment based upon the performance enhancement