# Evaluation of Airplane Boarding/Deboarding Strategies: A Surrogate Experimental Test

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## Abstract

**:**

## 1. Introduction

## 2. Design of a Surrogate Experimental Test

#### 2.1. Seat Layout and Dimensions

#### 2.2. Characteristics of Participants

#### 2.3. Boarding and Deboarding Strategies

- Random strategy: All participants are allowed to board in one group; each one of them is preassigned to a particular seat and enters the bus in no predefined order (see Figure 5a).
- WA strategy: Participants are divided into two groups according to the type of seats, aisle or window seat. The group with window seats board first, followed by the group with aisle seats; within each group, participants are essentially random (see Figure 5b).
- BF strategy: Participants are divided into several groups along the aisle (three groups in our experiment, indicated by BF3) and board in a back to front order; passengers are essentially random in each group (see Figure 5c).
- Steffen strategy: This method has the passengers lining up in a prescribed order that incorporates, in a specific way, boarding from the back to the front and from the windows to the aisle. Adjacent passengers in line are sitting two rows apart from each other in corresponding seats (e.g., 10D, 8D, 6D, 4D, 2D), so there is a total of eight successive groups (see Figure 5d).
- CRBF strategy: This strategy evolves from the Steffen strategy; one major improvement is that it allows for passengers who are sitting together to be adjacent in line (e.g., 10D, 9D, 8D, 7D, 6D). As seen in Figure 5e, there are a total of four successive groups distinguished by columns. Within each group, passengers are boarded in a back to front order. Here, we name this strategy as CRBF (Column rotated in a back to front order).
- Steffen-lug strategy: This method was first proposed in Reference [5] based on the Steffen strategy. The most prominent characteristic of this method is that the seats of passengers are assigned considering the number of luggage pieces they carry. Passengers are divided into eight successive groups and board the bus in a way that is similar to the Steffen strategy; within each group, passengers with more luggage enter the bus first.
- Free boarding strategy: This strategy is adopted by some budget airlines, such as Southwest in the United States and EasyJet in the UK. Rather than providing assigned seats, they do not offer any numbered tickets. The passengers choose their favorite seats and are free to sit in any available seats when entering the bus.

- AW strategy: Participants are divided into two groups, see Figure 5b. The group with aisle seat deplanes first followed by the group with the window seat, namely in an order of 2→1. Within each group, participants leave freely.
- FB strategy: Participants are divided into three groups (indicated by FB3), see Figure 5c. The groups of participants deboard in a front to back order, namely in an order of 3→2→1. Within each group, participants leave freely.

#### 2.4. Procedure

## 3. Time Delay in Boarding and Deboarding

#### 3.1. Seat and Aisle Interferences in Boarding

#### 3.2. Deboarding Time Delays

## 4. Experiment Results

#### 4.1. Boarding and Deboarding Time

#### 4.2. Time Gap

#### 4.3. Seat Preference in Free Boarding

## 5. Conclusions

- (1)
- The most time-saving strategies are those defining an exact sequence of the passengers when boarding, i.e., Steffen, CRBF, and Steffen-lug. They are fairly efficient because they eliminate seat interferences and, as much as possible, aisle interferences while allowing multiple passengers to stow their luggage simultaneously. In the light of this standard, the commonly used BF strategy is inefficient, even worse than the Random strategy.
- (2)
- Those time-saving strategies are also time stable, so they benefit both airlines and airport operators to make a reliable schedule.
- (3)
- All the strategies are sensitive to the quantity and quality of luggage taking by the passengers. If the airlines restrict the number pieces of luggage a passenger can take, as well as its weight and size, there will be no apparent difference between various strategies. If not, the strategy considering the luggage distribution is much more efficient, i.e., Steffen-lug, since it largely reduces the aisle interference between two successive boarding groups.
- (4)
- Both the experimental tests and the questionnaire survey reveal that the free boarding process is affected by passengers’ preference on the seat. This provides the opportunity to improve the free strategy by redesigning the seat size or layout in the cabin to change passengers’ preference on seats, and finally reduce the boarding time.

## Acknowledgments

## Author Contributions

## Conflicts of Interest

## References

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**Figure 5.**Five boarding strategies. WA = window to aisle manner; BF3 = back to front manner with 3 groups; CRBF = column rotated in a back to front order. (

**a**) Random; (

**b**) WA; (

**c**) BF3; (

**d**) Steffen; (

**e**) CRBF.

**Figure 8.**Deboarding in an unstructured manner. (

**a**) t = 17 s; (

**b**) t = 49 s; (

**c**) t = 52 s; (

**d**) t = 57 s.

**Figure 10.**The number of participants dealing with luggage simultaneously is three in (

**a**) and four in (

**b**).

**Figure 11.**Phenomenon of local congestion in BF3 strategy. (

**a**) t = 19 s; (

**b**) t = 27 s; (

**c**) t = 41 s; (

**d**) t = 44 s.

**Figure 13.**Time gap of getting through the bus gate. (

**a**) Random; (

**b**) Free; (

**c**) BF3; (

**d**) WA; (

**e**) Steffen; (

**f**) CRBF; (

**g**) Steffen-lug.

Number of luggage pieces | 0 | 1 | 2 |

Number of participants | 6 | 28 | 6 |

Abbreviations | Explanation |
---|---|

Random | Board in a random manner |

WA | Board in a window to aisle manner |

BF | Board in a back to front manner |

Steffen | Board according to the Steffen method |

CRBF | Board in a manner of column rotated with a back to front order |

Steffen-lug | An improved Steffen strategy considering luggage distribution |

Free | Select seat freely when boarding |

AW | Deboard in an aisle to window manner |

FB | Deboard in a front to back manner |

Unstructured | Deboard without any instruction |

Strategies | Test 1 | Test 2 | Test 3 | |||
---|---|---|---|---|---|---|

Boarding Time | Deboarding Time | Boarding Time | Deboarding Time | Boarding Time | Deboarding Time | |

Free | 3:10 | 1:49 | 3:00 | 1:40 | 3:04 | 1:43 |

Random | 2:29 | 1:44 | 2:38 | 1:39 | 2:47 | 1:41 |

WA | 2:26 | 1:33 * | 2:03 | 1:36 * | - | - |

BF3 | 2:39 | 1:39 * | 2:52 | 1:37 * | - | - |

Steffen | 2:11 | 1:38 | 2:09 | 1:36 | - | - |

Steffen-lug | 2:15 | 1:42 | 2:08 | 1:37 | - | - |

CRBF | 1:54 | 1:39 | 2:01 | 1:42 | - | - |

Attitude | Division 1 | Division 2 | |||
---|---|---|---|---|---|

Head | Middle | Rear | Window Seats | Aisle Seats | |

Like | 46% | 42% | 12% | 79.3% | 12.7% |

Dislike | 30.7% | 3.3% | 66% | 40.7% | 59.3% |

© 2017 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

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**MDPI and ACS Style**

Qiang, S.; Jia, B.; Huang, Q.
Evaluation of Airplane Boarding/Deboarding Strategies: A Surrogate Experimental Test. *Symmetry* **2017**, *9*, 222.
https://doi.org/10.3390/sym9100222

**AMA Style**

Qiang S, Jia B, Huang Q.
Evaluation of Airplane Boarding/Deboarding Strategies: A Surrogate Experimental Test. *Symmetry*. 2017; 9(10):222.
https://doi.org/10.3390/sym9100222

**Chicago/Turabian Style**

Qiang, Shengjie, Bin Jia, and Qingxia Huang.
2017. "Evaluation of Airplane Boarding/Deboarding Strategies: A Surrogate Experimental Test" *Symmetry* 9, no. 10: 222.
https://doi.org/10.3390/sym9100222