Airport Security. Simulation. Performance Metrics. The TRB Annual Sunday. Simulation. Workshop. January 12, Gensler

Transcription

1 Airport Security Simulation Performance Metrics The TRB Annual Sunday Simulation Workshop January 12, 2003

2 Introduction Security simulations are complicated by the different types of situations to be evaluated: SSCP, Bag screening, and Protection from explosive forces. What range of simulation tools are available? Algebra, Spreadsheet models, and Dynamic simulation.

3 Metrics to Be Used for Simulating Airport Security

4 Basic SSCP Model Inputs Design Day Schedule Pax Arrival Distribution Curves 0001h-0900h Domestic 0901h-2400h Domestic International Pax Demographics Load factor Origin and destination (O&D) ratio Design increase (optional) Screening Equipment Number of equipment groups (X-ray and magnetometer) Service rate per machine group Location-specific processing rate Consideration of selectees and employees

5 Basic EDS/ETD Model Inputs Similar to SSCP inputs, plus Demographics Bag/passenger ratio International/domestic connect rate (for international) Selectee rate EDS Processing Rates Number and type of equipment Screening protocols Optional Airline last-bag closeout time (for bag screening)

6 Basic SSCP Queue Model Landside Pax Arrival Rate SSCP Queue SSCP Rate Airside Pax Rate per station # of stations Design Day Schedule Arrival Distribution Load Factor O&D Ratio

7 Passenger Distribution Curve PASSENGER ARRIVAL DISTRIBUTION - Domestic before 9:00 AM Min. Percent % % % % % % % % % % % % % % % % % % % % % % % % 0 0.0% Percent of passengers each 10 minutes 20% 15% 10% 5% 0% Typical Enplanement Arrival Distribution Domestic Enplanements before 9:00 AM Minutes Before Departure Avg. arrival time = 65 minutes Std. Deviation = 0.40

8 Spreadsheet-Based Simulation Engine Airl DFlt Clock 00:00 00:10 00:20 00:30 00:40 00:50 01:00 01:10 01:20 Time 05:45 Pax : Pax : : Dep. 08: Time 09: : : : Arrival Distribution Table,offset)*pax : : : : : : Sum by clock interval 15: :

9 Solve for Equipment to Provide Zero Queue at Different Process Rates 15 SSCP Requirements for Zero Queue LAX T-1 SINC-T Design Day Schedule 08/00 Number of Units Pax/hour/lane 180 Pax/hour/lane 220 Pax/hour/lane 0 Time of Day 0.90= Load Factor 0.10= Design Increase 0.95= O&D Ratio

10 Solve for Queue Size 180 Pax/hr SSCP Queue Size LAX T-1 SINC-T Design Day Schedule 08/ Max Queue in Terminal 00:00 01:00 02:00 03:00 04:00 05:00 06:00 07:00 08:00 09:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 19:00 20:00 21:00 22:00 23:00 00:00 Pax in Queue Time of Day 10 Positions 9 Positions 8 Positions 0.90= Load Factor 0.10= Design Increase 0.95= O&D Ratio

11 Solve for Queue Time per Passenger 180 Pax/hr SSCP Delay LAX T-1 SINC-T Design Day Schedule 08/ Positions 9 Positions 8 Positions 00:00 01:00 02:00 03:00 04:00 05:00 06:00 07:00 08:00 09:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 19:00 20:00 21:00 22:00 23:00 00:00 Minutes to clear SSCP Time of Day 0.90= Load Factor 0.10= Design Increase 0.95= O&D Ratio

12 A Somewhat More Detailed SSCP Queue Model Landside Pax Arrival Rate Queue SSCP Primary Mag Rate Clear? Airside Pax SSCP Secondary Queue Wand Rate Clear? LEO

13 An Even More Detailed SSCP Queue Model Landside Pax Arrival Rate Bags Pax Pax Queue Wand Rate Clear? Pax Queue Mag Rate Clear? Bag Queue X-ray Rate Clear? Bag Queue ETD Rate Clear? Pax Queue Bag Queue Airside Pax

14 How Detailed Does It Need to Be? Unit 1 Int. Connects Arrival Rate Unit 2 Landside Pax 1 st Class? Selectees Airside Pax Unit 3 Employees Master Queue

15 What Type of Simulation Information Does a Designer Need? Number of pieces of equipment; Spatial characteristics of installation; Number of passenger/bags/employees to be accommodated in the queue; and Blast protection: Explosive charge weight, Location of charge relative to structure, and Basic structural plans and assessment of building envelope.

16 Potential Problems with Simulation Designer concerns: How long does it take to collect detailed info? How does it affect project rate and schedule? Does random variation really matter? Are solutions too tightly linked to assumptions? Lack of TSA responsiveness in providing design criteria and information. The designers perspective is the creation of physical space, not quantitative sophistication for its own sake.

17 Considerations That Are Not Easily Simulated

18 Physical Physical space impacts throughput; Space available may not accommodate the simulation recommendations; Processing through multiple decision points; Overlapping queues; and Unique architectural conditions.

19 Other Factors Operational: Equipment does not equal staffing; Equipment downtime; Downstream queues due to secondary screening; and The Southwest Airlines factor Behavioral: Changes in human behavior, Season/weather (coats, packages), and Traveler sophistication.

20 Example: Space Impacts Throughput Observed Passenger Processing Rate by Terminal # of Pax/hr/lane Min Max Average 50 0 Terminal 1 Terminal 2 Terminal 3 Terminal 4 Terminal 5 Terminal 6 Terminal 6/7 East Terminal 6/7 West Terminal 7A Terminal 7B

21 Example: Lack of Space for Recommendation

22 Example: Overlapping Queues

23 Problem: Multiple Decision Points

24 Example: Queue Outside the Building

25 Example: Unique Architectural Conditions

26 Queue Length and Duration, and Acceptable Level of Service

27 Queue Length and Duration and Acceptable Levels of Service Establish when the queue starts and when it ends in the process. Agree on the acceptable delay criteria (i.e., 85% in 10 min or less?). Consider what happens to the other 15%. Consider when queues exceed the space available even if within an acceptable LOS. Other overriding concerns: Life safety (blocked exits, other threats to assembly areas); and Maintaining visual continuity and wayfinding for passengers in increasingly congested areas.

28 Example: Average Delay and Level of Service 180 Pax/hr SSCP Delay LAX T-1 SINC-T Design Day Schedule 08/00 Minutes to clear SSCP :00 01:00 02:00 03:00 04:00 05:00 06:00 07:00 08:00 09:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 19:00 20:00 21:00 22:00 23:00 00:00 Time of Day 10 Positions 9 Positions 8 Positions Estimated Delay # of SSCP lanes Pax delayed >10 min 431 2,163 12, = Load Factor total 0.10= paxdesign Increase % delayed 0.95= >10 O&D min Ratio 21, % 21, % 21, %

29 Summary What metrics are useful in simulating airport security? Those that are readily available, simple to apply, and don t delay the design process. There are considerations affecting model performance that are not easily simulated: Physical, operational, and behavioral ones. Establishing the correlation between queue length and duration, to achieve acceptable LOS requires: Clear, mutual understanding among stakeholders of the inputs and assumptions used for the simulation and to calculate the LOS. Recommendation: Use the simplest model possible to establish basic design, and more complex ones to validate design, tune procedures, and test sensitivity.

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