the decision model for aircraft stand allocation · t1 t2 t3 t4 t5 t6 t7 t8 t9 flight 1 is delayed...

THE DECISION MODEL FOR AIRCRAFT STAND ALLOCATION

librt.comsilvie spreeuwenberg.com

What do you know about airports?

What decisions are made to manage an airport?

What do we knowabout Schiphol?

Passengers

Transfers

Flights

Fright

Handlers

Finance

Safety

Remote handling

On time performance

Slots

Runway

Noise

Layout

Strategy: close gap between strategy and executionRelationship between policy & strategy, management & tactics and operation & execution.

Strategy: rule based approach for traffic managementLess rules,

simple rules,

small units,

data driven,

agent based control mechanism,

optimize flow,

goal variable.

landelijke regelaanpak.nl

Question

"Why are there so many gate changes?"

From C18 to C08From C08 to C05From C05 to D1

Is a gate change an optimization or a disruption?

50-100 gate changes per day 1 hour before arrival.

Silvie in thecontrol tower

Day shift

Morning shift

Night shift

GATE PLANNING

1

3

5

Day ahead planning

The day ahead plan: same agents (same color tone) in adjacent ramp, airlines (same color) after each other, optimal turn over factor, maximal

separation time.

7

9

11

Agent A

Agent B

Agent C

REALITY

NO IDEAL PLAN?1

3

5

Flight 1 Flight 2

Flight 3

Flight 5Flight 4

day-ahead planning

t1 t2 t4 t5 t6 t7 t8 t9t3

The day-ahead planning: Everything has a place...

++1

3

5

Flight 1

Flight 2

Flight 3

Flight 5

Flight 4

On-Day planning T3 – Gate Change Flight 2 and 5

t1 t2 t4 t5 t6 t7 t8 t9t3

Gate modification to avoid risk of waiting flight 2.

++1

3

5

Flight 1 Flight 2

Flight 3

Flight 5Flight 4

On-day planning t2

t1 t2 t4 t5 t6 t7 t8 t9t3

Flight 1 is delayed on departure.

++1

3

5

Flight 1

Flight 2

Flight 4

On-Day Planning T5 – Gate Change Flight 2, 3 and 5

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-- Flight 5

++ Flight 3

1

3

5

Flight 2

Flight 3

On-day planning t6 – evaluatie

t6 t7 t8 t9


-- Flight 5

1 change

2 changes

2 changes

++

--++1

3

5

Flight 1

Flight 2

Flight 3

Flight 5

Flight 4

On-day planning t4

t1 t2 t4 t5 t6 t7 t8 t9t3

Flight 1 is delayed on departure .

Planned work

Which aircraft stand is assigned to flight?

Regulation Aircraft Stand Allocation

Schiphol

A. Should a flight be assigned to a gate?

B. Which gates may accommodate the flight?

Flight type (K, W, unknown)

AAS opstelplaatsentabe

l maatgeving

Aircraft category / type

C. Which gates are mandatory for flight?

D. Which gate or platform is agreed with airline?

Accountmanager airline

Destination

Origin

Flight STA

Airline

# dep. pax

E. Which gate has minimal distance to

transfer gates?Which aircraft stands are available for flight?

# transfer. pax

Distance between gates / floorplan

Clearing time + Seperation time

Lijst met bolletjes landen

F. Which gate will avoid the risk on future delays? Gate planners

Categorie tabel vliegtuig type

Flight number

G. Which gate is closest to gates handled by the

same agent?Handling agent

Relevant criterium not in GMS

Decision / sub decision

Human knowledge source

Formal knowledge source (document or policy)

Criteria for decision

Schengen, EU, NEU

Dependency is a result of implementation decision in GMS

tow

DECISION MODELaircraft stand assignment

day ahead planning

DECISION MODEL

aircraft stand update (on day planning)

Based on October / November 2017 - data extracted from CISS

Should the aircraft stand allocation be changed for

a flight

B. Assigned gate can accommodate the flight?

H. Assigned gate for arriving flight is available

on EIBT?

I. Is the time between flights too short or overlaps?

C. Assigned gates is mandatory for flight?

New flight registration

New EIBT

New TOBT

New flight for gate

Planned work


l maatgeving


Lijst met bolletjes landen

Schengen, EU, NEU

Clearing time + seperation time

0.3%

62%

17%

?#

Percentage of flights that update the aircraft to a larger aircraft on the day of operations

Percentage of flights that update the EIBT on the day of operation and may disturb the plan.

Percentage of flights that update the TOBT on the day of operation and may disturb the plan

Percentage of flights that change gate due to another flight scheduled on the gate

Category

Length Wid

th

Rushhour

Season Min

utes

Rushhour

Season Min

utes

DECISION MODEL

New aircraft stand(on day planning)

J. Option to include pit stop?

Handler has tow capacity

Bus planning has bus capacity

Apron control has taxi capacity

How to solve a capacity problem for an aircraft

stand allocation ?

M. Option to switch flight of adjacent ramps

O. Option to use bus gate

L. There is a holding position to wait for the

assigned gate

K. Option to create a tow?

N. Option at other pier

Promote outbound

Decrease inbound

Reroute

Handling agent may reach and handle at the

new ramp.

Objective: on time performance

Estimated flight timemargin margin

On time departure from Heathrow Early arrival at Schiphol

On time arrival from HeathrowDelayed departure from Heathrow

Exceptional long flight time

Scenario 1

Scenario 2

Scenario 3

All parties allow for some flexibility in the plan, consequently, the scheduled and actual times are never the same by design.

What does on time performance mean?

Estimated flight timemargin margin

On time departure from Heathrow Early arrival at Schiphol

On time arrival from HeathrowDelayed departure from Heathrow

Exceptional long flight time

Scenario 1

Scenario 2

Scenario 3

All parties allow for some flexibility in the plan, consequently, the scheduled and actual times are never the same by design.

Less margins

More capacity

Increase trust

Share data

Objective: optimize use of assetsWide wing aircraft occupies three gates

The gate that is for a departing flight must have a waiting area capacity that is at_least the number of departing passengers ofthe flight.

Strategy: rules approach

# Status Rule Condition Location 1 Cost dep pax>= 201 in D41 2 Cost dep pax>= 201 in E02 3 Cost dep pax>=275 in D43, D47 4 Cost dep pax>= 300 in F08

Strategy: decision model

Planned work

B. Which ramps may accommodate a flight?

Flight type (K, W, unknown)


l maatgeving

Aircraft category / type

Airline# dep. pax


tow

Strategy: deal with disruptions

Terminal capacity

Ground capacity

Air capacity

Air capacity, ground capacity and terminal capacity are related

Strategy: capacity communication framework

capacity class / situation

flexible saturation congestion gridlock

The capacity class for an asset is a real time indicator that shows how the usage of the capacity may influence on time performance.

Be radical transparent and adapt rules to minimize the consequence of disruptions when capacity is optimal used.

motto

Is there one solution?

Reroute traffic by a gate change

Promote outbound

traffic by towing

Decrease inbound traffic

by holding

Gate capacity Air capacityHolding capacity Pier capacity Security capacity Pick up point capacityApron capacity

The capacity of different stakeholders in the chain is related and may all be the bottleneck at some point in time.

Measure capacity usage on links in the network

seperation time threshold / ramp situation

> 20 min > 10 min > 2 min < -2 min

lowest delay alternative / pier situation

> 1 = 0 = -1 < -2

alternatives / aircraft stand allocation situation

> 1 > 0 = 0 < 0

holding time / holding position situation

> 2 > 0 = 0 < 0

The ramp situation is a capacity class for an occupied ramp based on the expected separation time with the following flight.

The pier situation is a capacity class for a pier based on the lowest number of alternative gates in the pier for the next planned flight allocation at each gate

The aircraft stand allocation situation is a capacity class for an aircraft stand allocation based on the number of alternative gates available for the flight.

The holding position situation is a capacity class for Schiphol that indicates the total holding time of all aircrafts standing at a holding position.

Example of capacity classes for different kinds of assets

Keep it simple

Decision logic for a service request based on actual capacity situation

Capacity

class:Flexible Saturation Congestion Grid lock

Promote

outbound?- Request Request Request

Limit

inbound?- - Request Request

Reroute? - - - Request

Be radical transparent and adapt rules to minimize the consequence of disruptions when capacity is optimal used.

Small steps

Policy document is updated

RASAS

Regulation for AircraftStandAllocationSchiphol

https://www.schiphol.nl/en/operations/page/aircraft-process/

Less proza, less pages

Follows the structure of the decision model

Seperate chapter for day ahead decisions and

handling disruptions

All guidelines expressed as constraints

More decision tables

Example document for all other plan processes.

Small steps

Policy document is updated

RASAS

Regulation for AircraftStandAllocationSchiphol

https://www.schiphol.nl/en/operations/page/aircraft-process/

Small steps Example decision table

Small steps Motivated principles expressed as a constraint

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the decision model for aircraft stand allocation · t1 t2 t3 t4 t5 t6 t7 t8 t9 flight 1 is delayed...

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