This was my 3rd year SIMUL8 software coursework in which I had to analyse the check-in and boarding process involving a number of passengers and find ways to improve it.

1. 396EM – AIRLINE OPERATIONS AND SCHEDULING
(Consumer Affairs 2019)
AIRLINE BOARDING INTERFERENCE PROBLEM II
WRITTEN BY:
Tudor Daniel Mihailov
SID:
7154843

2. 1
TABLE OF CONTENTS
INTRODUCTION ....................................................................................................................................... 2
TABULAR FORM ....................................................................................................................................... 3
FLOWCHART ............................................................................................................................................ 4
SIMULATION SCENARIOS ......................................................................................................................... 6
“As-Is” Scenario ................................................................................................................................... 6
“What-If” Scenario .............................................................................................................................. 7
“What-If 2” Scenario ........................................................................................................................... 8
Overall Comparison ........................................................................................................................... 10
CONCLUSIONS ....................................................................................................................................... 11
RECOMMENDATIONS ............................................................................................................................ 11
REFERENCES .......................................................................................................................................... 12
LIST OF FIGURES
Figure 1: Flowchart representing the boarding process .................................................................................. 4
Figure 2: “As-Is” simulation model ................................................................................................................... 6
Figure 3: “As-Is” simulation model queue times .............................................................................................. 6
Figure 4: “What-If” simulation model .............................................................................................................. 7
Figure 5: “What-If” simulation model queue times ......................................................................................... 8
Figure 6: “What-If 2” simulation model ........................................................................................................... 8
Figure 7: “What-If 2” simulation model queue times ...................................................................................... 9
Figure 8: Overall comparison of simulation scenarios .................................................................................... 10
LIST OF TABLES
Table 1: Airport Operations tabular form ........................................................................................................ 3

3. 2
INTRODUCTION
The boarding process is usually the last step that passengers have to go through when departing from an
airport. It can get complex as the scale of the operation increases; however, this report is going to be about
the boarding process of 40 passengers. They are traveling on the same class and have all the same attributes.
Passengers arrive at the boarding gate on the basis of the Excel file which can be found in the same folder.
The problem that the airport encounters is that they have to optimise the flow of the operations in order to
reduce the boarding times. On their way, to the seats, passengers encounter 4 queues, namely: Gate Desk
queue, Seat Interference queue, Aisle Interference queue and Overhead Bin Interference queue.
The main of the airport is to improve the overall boarding process, by reducing by as much as possible the
queue waiting times for the gate desk and the 3 disruptions that happen in the aircraft.
The objectives of this simulation are:
• To analyse the airline boarding process
• To develop a flow chart for the process
• To develop the business and simulation model
• To run “As-Is” and 2 “What-If” scenarios
• To compare the data before and after the proposed improvements
The tools used in order to do this are going to be:
• Tabular forms
• Scenarios
• SIMUL8
• Graphs
• Figures
The KPI’s that are going to be tracked over the period of the simulation are:
• Gate Desk queue average waiting time
• Seating Interference queue average waiting time
• Aisle Interference queue average waiting time
• Overhead Bin Interference queue waiting time
• Overall average simulation time

4. 3
TABULAR FORM
SYSTEM ENTITIES ATTRIBUTES ACTIVITIES EVENT STATE VARIABLE
Airport
operations
Passengers
(temporary)
Booking
confirmation
Ticket number
Ticket type
Destination
Passport
Boarding pass
Walk to gate
agent
Hand-over
boarding pass
Walk through
air bridge
Enter aircraft
Search for seat
Put luggage in
overhead bin
Take a seat
Arrival
Departure
Queue length
Average waiting
time
Average
boarding time
Resources
(Permanent)
Terminal
Gate agents
Gate desks
Air bridges
Aircraft
Boarding
operation
Documents
check
Guidance to
aircraft
Assistance in
aircraft
Idle
Busy
Working hours
Utilisation
Table 1: Airport operations tabular form

5. 4
FLOWCHART
Having a flowchart for such type of operation, helps in more easily identifying the logical flow of actions and
makes for an easier identification of possible bottlenecks. This could lead to an faster fix of those areas. Also,
by having a flowchart in front of you, it makes it easier to identify all the processes that happen during the
boarding operation. This enables the executives and analysts to clearly see what each passenger has to go
through and could work towards smoothing the entire process. Timing could also be improved by reducing
the duration of each different step.
Figure 1: Flowchart representing the boarding process

6. 5
The flowchart above is meant to schematically illustrate the boarding process that the passengers need to
follow. Although it might look quite intimidating at the beginning, the logic behind it is easy to follow.
First, passengers arrive at the boarding gate and form a queue before they are called to have their
documents checked by the gate agent. If they are not called to the gate, they have to stay in the queue
longer.
When asked, they need to go to the gate agent and give him the boarding pass for it to be checked. The gate
agent checks the pass and the passengers need to stay there. If the check is not done yet, they have to wait
there for a little more.
After the check is done, they need to proceed through the air bridge in order to enter the plane. If there is a
queue at the entrance of the plane, they have to wait in the queue. When it is their turn, they have to
proceed to the allocated row. If the passenger didn’t reach the allocated row, he has to search more in the
aircraft.
When the passenger reached its allocated row, he/she has to put the luggage in the overhead bin
compartment. If they didn’t put the baggage, they have to search more until they find a place for the luggage.
When they found the place, they need to take a seat. If one passenger blocks the way of another one, he/she
has to sit up and let the other passengers pass. When all the passengers passed and the way is no longer
blocked, he can remain seated.
The boarding process if done when all the passengers are seated correctly, and all the luggage is adequately
placed in the overhead bins, otherwise, the cabin crew has to wait until everyone is seated.
When everybody is seated, they can call “Boarding Completed”.

7. 6
SIMULATION SCENARIOS
“AS-IS” Scenario
The figure below illustrates the “As-Is” model of the simulation. It is comprised of a starting point
“Passengers Arrive”, a Gate Desk 1 queue, a Gate Desk 1 activity that has one resource (Gate Agent 1), an
Air Bridge that passengers have to walk through, the three interferences that passengers encounter and
their respective queues (Seat Interference, Aisle Interference and Overhead Bin Interference). Finally, there
is the ending point (Seated Passengers) that once it gets to 40 seated passengers, the simulation is
completed.
Figure 2: “As-Is” simulation model
In the form presented above, the following figures were achieved. They have been presented below in a bar
chart format, in order to make for an easier comparison later with the “What-If” and “What-If 2” models.
Figure 3: “As-Is” simulation model queue times

8. 7
At the first glance, it can be seen that in the “As-Is” scenario, the bottleneck places are the Gate Agent and
Aisle Interference. In the rest of the cases, the waiting times are somewhat acceptable. The overall
simulation time, however, was 84 minutes, which if we consider that it means almost one and a half hours
for 40 passengers to board, is quite bad.
“WHAT-IF” Scenario
The second scenario was the “What-If” scenario in which adding another Gate Agent entity has been tried,
in order to diminish the initial bottleneck from the first scenario.
Figure 4: “What-If” simulation model
This simulation model is not very different to the initial one, other than the fact that another gate desk
activity (Gate Desk 2), a Gate Desk Queue 2 and a gate agent resource (Gate Agent 2) have been added. In
addition to that, the working times of the documents check times have been reduced from 2-4 minutes to
1-2 minutes/ passenger. This has been done in order to enable the Gate Agents to process more people
quicker.
After condoning such changes, the following numbers have been obtained. In order to illustrate the changes,
the “What-If” figures have been compared to the “As-Is” ones.

9. 8
Figure 5: “What-If” simulation model queue times
As it can be seen, the strategy of opening a second gate desk (Gate Desk 2) and reducing the processing time
has helped reducing the amount of time people stand in the queue by 11 minutes, however, the bottleneck
moved now inside the plane. Apparently, all other queue times have increased and there is a simple
explanation to that. Too many people enter the aircraft at the same time through a single access point (the
Air Bridge) and then have to stand in all the queues for longer. The next what-if strategy tackles this
bottleneck and it can be found in the next section.
However, considering that all the interferences queue times have increased, the overall simulation time has
decreased by 5 minutes.
“WHAT-IF 2” Scenario
The third scenario is the “What-If 2” scenario, which proposes another air bridge (Air Bridge 2) to be opened
in order to facilitate the access from two points of the passengers to the aircraft. In addition to that, it
proposes that two cabin crew (Cabin Crew, Cabin Crew 2) are placed inside the aircraft and help passengers
find their seats faster as well as helping them place their luggage in the overhead bin.
Figure 6: “What-If 2” simulation model

10. 9
In addition to that, contrary to the “What-If” model, the “What-If 2” model sets the Gate Agent documents
check times back to the initial 2-4 minutes/ passenger. Moreover, thanks to the two cabin crew, the times
for Seating Interference have been reduced from the original 3-5 to 1-3 minutes, Aisle Interference has been
reduced from 5-10 to 3-5 minutes and the Overhead Bin Interference has been reduced from 4-7 to 2-3
minutes.
These changes could be sustained by the fact that a second air bridge would enable the passengers to enter
from two points, thus effectively reducing to almost half the interferences times. Also, the cabin crew help
inside the aircraft is a contributing factor.
Figure 7: “What-If 2” simulation model queue times
As it can be seen in the figures above, all the queue times have been reduced, some of them have even been
halved (Gate Agent queue time and Overall Simulation Time). It can be argued that this would be the most
effective option for truly optimizing the boarding process in this case. “What-If 2” is the option that would
require the biggest investment, but the results speak for themselves.

11. 10
Overall Comparison
The figures below represent the overall comparison of all three simulation models and the evolution of each
KPI according to the changes discussed in the sections above. It can be seen that opening a second gate desk
helped a certain amount fluidizing the passengers traffic but created a bottleneck in the aircraft.
On the other hand, the “What-If 2” model, had a greater impact on the overall performance of the simulation
and on each specific KPI.
In the figures above, it can be seen that the green bars, which represent the “What-If 2” scenarios, are lower
than the previous ones by almost half in all cases.
Gate Agent Queue Time went progressively from 62 to 51 to 29 minutes, Seating Interference Queue Time
from 0.57 to 0.60 to 0.55 minutes, Aisle Interference Queue Time from 10.29 to 14.85 to 7.06 minutes,
Overhead Bin Interference Queue Time from 2.19 to 2.36 to 1.36 minutes and the Overall Time from 83.77
to 78.54 to 44.78 minutes. Overall there has been an improvement of 6.24% from “As-Is” to “What-If” and
a decrease of 43% from “What-If” to “What-If 2”.
Figure 8: Overall comparison of simulation scenarios

12. 11
CONCLUSIONS
Each of the objectives mentioned above have been accomplished by the use of relevant methodology and
practices:
• Objective 1 has been accomplished by providing the introduction to this report.
• Objective 2 has been accomplished by creating the flowchart in figure 1 and explaining it in the
paragraphs below it.
• Objective 3 has been accomplished by creating simulation models “As-Is”. “What-If” and “What-If 2”.
• Objective 4 has been accomplished by running the scenarios created above using the Simul8 software
and extracting KPI data.
• Objective 5 has been accomplished by creating the figure 6 in which all the KPI’s are compared against
each other.
The “Should-Be” scenario is the “What-If 2” scenario. This is the one that drastically improves all the KPI’s of
the boarding process by an average of 55% compared to the other two scenarios. It is true that this requires
more resources to be allocated but the results pay off because the process is going to be more efficient and
the airport will probably be able to operate more flights during the same time frame.
RECOMMENDATIONS
Further research could be done on this subject. It could focus on further analysing the impact of reducing
the waiting times on the airport’s financial performance. Meaning that the costs to revenue ratios should be
analysed to see if it is viable and sustainable for the airport to further reduce the waiting times by deploying
more resources.
Tools like SIMUL8 software as well as accountability principles can be used to forecast the impact that certain
improvements will have on the overall and financial performance of the airport.
Feedback from passengers could also be taken into consideration to determine if the changes that are being
done, help improve the overall travel experience of the passengers during their stay in the airport.

13. 12
REFERENCES
Consumer Affairs (2019) How new airline boarding procedures could curb the spread of diseases [online]
available from <https://www.consumeraffairs.com/news/how-new-airline-boarding-procedures-could-
curb-the-spread-of-diseases-090817.html> [22 April 2019]