Massive uncertainty
This presentation is the property of its rightful owner.
Sponsored Links
1 / 17

Massive Uncertainty PowerPoint PPT Presentation


  • 78 Views
  • Uploaded on
  • Presentation posted in: General

Massive Uncertainty. Dr. Richard de Neufville Professor of Systems Engineering and Civil and Environmental Engineering Massachusetts Institute of Technology. Massive Uncertainty. Objective: To present realistic context of forecasting exercise Topics Evidence Consequences.

Download Presentation

Massive Uncertainty

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Massive uncertainty

Massive Uncertainty

Dr. Richard de Neufville

Professor of Systems Engineering and

Civil and Environmental Engineering

Massachusetts Institute of Technology

Airport Systems Planning & Design / RdN


Massive uncertainty1

Massive Uncertainty

  • Objective: To present realistic context of forecasting exercise

  • Topics

    • Evidence

    • Consequences

Airport Systems Planning & Design / RdN


Causes of uncertainty

Causes of Uncertainty

  • Underlying variability of phenomenon

  • Difficulties in measurement or estimation

  • Unforeseen or “unpredictable” circumstances

  • Limits to valid measurement

    • for example: behavioral patterns

Airport Systems Planning & Design / RdN


Evidence

Evidence

1.Simple Physical Systems

2.Overall Traffic

3.Local Traffic (Worse)

4.Other Operations

Airport Systems Planning & Design / RdN


Ratio of real costs to estimated costs for airport projects

Ratio of Real Costs to Estimated Costs for Airport Projects

Costs expressed in constant dollars

Median ~= 1.25

Percent of Occurrences

Real/Estimated Cost Ratio

Airport Systems Planning & Design / RdN


Cost growth for various projects

Cost Growth for Various Projects

3.0

2.5

2.0

1.5

1.0

0.5

0.0

Ratio of Actual to Estimated Cost

DOD60 HWAY WATER BLDNG DOD50 ADHOC MAJOR ENRGY NASA NASA AVG St.Dev.

CONST SAT mg

Airport Systems Planning & Design / RdN


Nasa projects cost growth

NASA Projects Cost Growth

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0.0

Ratio of Actual to Estimated Cost

HST GLL UARS GRO COBE MGL MOBS LSAT EUVE ERBE AVG St.Dev.

Airport Systems Planning & Design / RdN


Forecasting errors

Forecasting Errors

Nature of

Traffic

Type of

Traffic

Percent Error which is Exceeded Half

the Time after Each year

One

Year

Two

Years

Three

Years

Four

Years

Five

Years

Six

Years

International

US Domestic

Passengers

Pax-Miles

Average

Passengers

Pax-Miles

Average

8.0

7.2

7.6

2.9

2.9

2.9

10.9

10.9

10.9

6.2

6.0

6.1

14.0

13.8

13.9

11.2

10.6

10.9

14.0

15.7

14.9

14.1

14.5

14.3

15.1

16.7

15.9

18.3

18.3

18.3

15.8

19.5

17.6

20.4

21.8

21.1

Average Errors in the Forecasts of Air Traffic of the U.S. Federal Aviation Administration, 1958-71

Airport Systems Planning & Design / RdN


Faa forecasts compared with actual data difference

FAA Forecasts Compared with Actual Data (% Difference)

Review of the FAA 1982 National Airspace System Plan

Airport Systems Planning & Design / RdN


Forecast vs actual international pax in japan

Forecast vs. Actual International Pax in Japan

Airport Systems Planning & Design / RdN


Forecast vs actual international pax to japan

Forecast vs. ActualInternational Pax to Japan

Airport Systems Planning & Design / RdN


Forecast vs actual international pax in sydney

Forecast vs Actual International Pax in Sydney

Airport Systems Planning & Design / RdN


Massive uncertainty

ACTIVE GENERAL AVIATION AIRCRAFT

1980 FORECAST

Airport Systems Planning & Design / RdN


Massive uncertainty

ACTIVE GENERAL AVIATION AIRCRAFT

1985 FORECAST

Airport Systems Planning & Design / RdN


Massive uncertainty

ACTIVE GENERAL AVIATION AIRCRAFT

1990 FORECAST

Airport Systems Planning & Design / RdN


Massive uncertainty

ACTIVE GENERAL AVIATION AIRCRAFT

1998 FORECAST

Airport Systems Planning & Design / RdN


Summary and recommendations

Summary and Recommendations

  • Summary

    • Forecast Errors have been large

    • Likely to continue

  • Recommendations:

    • Expensive Forecasting is cost-ineffective

    • Use general trends

    • ...With large ranges

    • Flexible Approach to Planning!!!

Airport Systems Planning & Design / RdN


  • Login