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O&D Forecasting Issues, Challenges, and Forecasting Results. John D. Salch PROS Revenue Management, Inc. jsalch@prosrm.com. Forecasting Issues / Challenges. data processing time modeling dynamics. Data …There Is More Than We Know What to Do With. Data Collection.
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O&D ForecastingIssues, Challenges, andForecasting Results John D. Salch PROS Revenue Management, Inc. jsalch@prosrm.com
Forecasting Issues / Challenges • data • processing time • modeling • dynamics
Data Collection • Data Sources (Assume 1000 flights per day) • PNR (Touched and Flown) ~ 250,000 per day • Flight level inventory ~ 150,000 per day • Schedule ~ 20,000 per day • Agent, Customer, etc… ~ ? (your mileage may vary…)
Data To Collect: Some Examples • Ticketing Information • Currency (Type/Exchange Rate) • Fare Basis Code • Special Service • Passenger Address • OAL Booked By • OAL segment(s) • Tour Segment • Hotel Segment • Car Segment • Group Name • Number of Passengers in PNR • Ticket Type • Denied Boardings Code • Form Of Payment Info • Agent Iata# • Tel # • Other Supp. Info Messages • Protected History (all legs bkd) • Received From (PNR modifying person) • Arrival Times all legs • OAL segment • PNR Record Locator • Passenger Name • Creation Time • Creation Date • Creation DOW • Holiday • Special Events • Airline Code(s) • Origin Airport • Origin City • Origin Country • Origin Continent • Destination Airport • Destination City • Destination Country • Destination Continent • Path Airport • Path City • Departure Date(s) all legs • Departure Time(s) all legs • Point of Sale City • Point of Sale Country • Point of Sale Continent • Booking Office • Group Identifier • Passenger Type (Freq. Flier Type?) • Frequent Flier Number • Fare Classes all legs • Number of Passengers • Number Protected • No Show Identifier • No Show Reason • Go Show Identifier • Go Show Booking Time before Departure • Connection from Airline • Connection to Airline • Original Point of Departure • Final Destination • Cancellation Identifier • Cancellation Date • Cancellation Time • Cancellation Reason • Flight Numbers all legs • Confirmation Codes all legs • Fare (Base, Airport Chg, Tax)
Data Challenges • Rich source of data • It will take many years to find all of the gems • Large volumes of data • Processing time is the binding constraint • Cleaning / Massaging • Lots of cleaning required
Forecast Updating • Unconstrain Actuals • Update Models
Unconstraining • Methods for adjustment • Projection Methods • Iterative Methods • Inputs • Constraint Probability • Bookings / Cancels / Waitlist
Forecast Modeling • Bayesian forecasting paradigm • Correlation adjustments • Seasonality Adjustments • Hierarchical Correlation • Component Relationship
Bayesian Forecasting • Simple updating • Minimal data history required • Uses all history, but minimize database • Dynamic to changing data • exponential smoothing
Bayesian Forecasting • components: • reservations (arrivals model) • cancellations (rate model) • go-shows • no-shows • booking curve • Each component poses new challenges!
Correlation Adjustment • remove model assumptions of independence across time slices • adjust based on correlation model • early surge in bookings/cancels may result in lower or higher bookings later in cycle • significant reduction in errors
Seasonality Adjustments • Model cyclical patterns • day of week patterns • monthly patterns • year over year patterns • significant reduction in errors
Hierarchical Adjustments • remove model assumptions of independence between entities • relate entities through hierarchy • reduce “small numbers” problem • high demand in one itinerary may imply high/low demand in another (spill) • significant reduction in errors
Component Relationship • “Blend”: • blend different models to form “out” passenger forecasts, demand to come • relate forecasts, e.g. cancels and no-shows
Accuracy: “The Forest and the Trees” • Small numbers accurate, but... • aggregations need to be accurate, as well • Feedback mechanism • proper model tuning • bad aggregate forecasts can bias bid prices
Holidays / Special Events • Accounted for in models • Discount from “non-holiday” forecasts • Incorporate user knowledge
Dynamics • Schedule changes • Reduce impact of frequent changes in the flight network • Maintain “relevant” history • Create a “schedule-free” network • Accounting for new markets • sponsorship
Hard Work Pays off... Forecasting Results
A Forecast "Tonight's forecast: dark. Continuing dark throughout the night and turning to widely scattered light in the morning." - George Carlin