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Massive Uncertainty

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

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Massive Uncertainty

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  1. Massive Uncertainty Dr. Richard de Neufville Professor of Engineering Systems and Civil and Environmental Engineering Massachusetts Institute of Technology Airport Systems Planning & Design / RdN

  2. Massive Uncertainty • Objective: To present realistic context of forecasting exercise • Topics • Evidence • Consequences Airport Systems Planning & Design / RdN

  3. 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

  4. Evidence 1. Simple Physical Systems 2. Overall Traffic 3. Local Traffic (Worse) 4. Other Operations Airport Systems Planning & Design / RdN

  5. 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

  6. Cost of asphalt rising Local road repairs are likely to lag By Kay Lazar, Globe Correspondent June 8, 2006 http://www.boston.com/news/local/articles/2006/06/08/cost_of_asphalt_rising/ The soaring cost of petroleum -- a primary ingredient of asphalt -- has forced many communities to shoulder a 50 percent increase in costs as crews head out to repave roads this summer. Asphalt sticker shock is creating heartburn for legions of highway chiefs, prompting many to significantly curtail the number of roads they intend to repair this season. And the going may get even tougher. Two major asphalt suppliers for the region are warning of another 50 percent increase by Thanksgiving -- in addition to potential shortages Airport Systems Planning & Design / RdN

  7. 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

  8. 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

  9. Results of a 2004 study Adapted from: Terminal Area Forecast (TAF) Accuracy Assessment Results Jerome Friedman, MITRE CAASD, Sept. 30, 2004 Airport Systems Planning & Design / RdN

  10. Results of a 2004 study Adapted from: Terminal Area Forecast (TAF) Accuracy Assessment Results Jerome Friedman, MITRE CAASD, Sept. 30, 2004 Airport Systems Planning & Design / RdN

  11. Recent Error Data from U.S Source: MITRE CAASD and FAA Airport Systems Planning & Design / RdN

  12. Recent Error Data from U.S Source: MITRE CAASD and FAA Airport Systems Planning & Design / RdN

  13. Actual vs. Forecast 10 years earlierSource: FAA Aerospace Forecast FY 2006-2017 Note: These are aggregate NATIONAL data, in which greater local variations tend to cancel each other out Airport Systems Planning & Design / RdN

  14. Older FAA Forecasts vs. Actual Data (% Difference) Review of the FAA 1982 National Airspace System Plan Airport Systems Planning & Design / RdN

  15. Forecast vs. Actual International Pax in Japan Airport Systems Planning & Design / RdN

  16. Forecast vs. ActualInternational Pax to Japan Airport Systems Planning & Design / RdN

  17. Forecast vs Actual International Pax in Sydney Airport Systems Planning & Design / RdN

  18. ACTIVE GENERAL AVIATION AIRCRAFT 1980 FORECAST Airport Systems Planning & Design / RdN

  19. ACTIVE GENERAL AVIATION AIRCRAFT 1985 FORECAST Airport Systems Planning & Design / RdN

  20. ACTIVE GENERAL AVIATION AIRCRAFT 1990 FORECAST Airport Systems Planning & Design / RdN

  21. ACTIVE GENERAL AVIATION AIRCRAFT 1998 FORECAST Airport Systems Planning & Design / RdN

  22. 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

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