# Difference: AirCrewRostering (8 vs. 9)

#### Revision 92008-05-07 - TWikiAdminUser

Line: 1 to 1

 META TOPICPARENT name="SubmitCaseStudy"
`<-- Under Construction -->`
Line: 80 to 80

Added:
>
>

 META FORM FORM FIELD Title name="OpsRes.CaseStudyForm" Title AirCrewRostering DateSubmitted 20 Feb 2008 CaseStudyType DIYCaseStudy OperationsResearchTopics IntegerProgramming
Changed:
<
<
 FORM FIELD ApplicationAreas ApplicationAreas
|*FORM FIELD ProblemDescription*|ProblemDescription|*THE AIR CREW ROSTERING PROBLEM*

Adapted from a real-world problem

An airline is trying to roster captains for 6 flights. The flight schedules are:

Only one captain is required for each sector, but a captain may be a passenger on a flight (this is called paxing). In addition to the six flights above the following flights are available for paxing and operate every 2 hours:

The following rules for shifts must be observed:

• Shifts start and finish at a captain’s home base;
• The earliest start time is on Day 1 (0001 hours) and the latest finish time is on Day 6 (2359 hours);
• Shifts are composed of blocks of work. Each block must be no more than 13 hours;
• Captains must have at least 12 hours break between blocks. The exception is when a block consists only of paxing flights, then a 9 hour break is all that is needed;
• There must be a 30 min break between sector changes.

There are 6 captains available for work, 2 based in Auckland (AKL), 1 based in Christchurch (CHCH) and 3 based in Singapore (SNG). Each captain is paid \$1000 for each block of work (even if it is only a 45 min pax). Each captain’s contract guarantees he/she will be paid for 3 blocks of work even if they perform less.

The airline has started an AMPL model, but given up:

FLIGHT_SCHEDULE.MOD

```model;

set TODS; # T(our) O(f) D(uty) set = pilot schedules
set FLYS {TODS} within FLIGHTS;

param Blocks {TODS} integer >= 1;
param Base {TODS} symbolic within BASES;
```

They have asked you to complete their model file and write a data file and script file to solve their rostering problem.

The airline is also curious if they can reduce the cost of their roster by using less pilots. As a second deliverable, they have asked you to investigate this option. |

>
>
 FORM FIELD ApplicationAreas ApplicationAreas Rostering
|*FORM FIELD ProblemDescription*|ProblemDescription|*Adapted from a real-world problem*

An airline is trying to roster captains for 6 flights. The flight schedules are:

Only one captain is required for each sector, but a captain may be a passenger on a flight (this is called paxing). In addition to the six flights above the following flights are available for paxing and operate every 2 hours:

The following rules for shifts must be observed:

• Shifts start and finish at a captain's home base;
• The earliest start time is on Day 1 (0001 hours) and the latest finish time is on Day 6 (2359 hours);
• Shifts are composed of blocks of work. Each block must be no more than 13 hours;
• Captains must have at least 12 hours break between blocks. The exception is when a block consists only of paxing flights, then a 9 hour break is all that is needed;
• There must be a 30 min break between sector changes.

There are 6 captains available for work, 2 based in Auckland (AKL), 1 based in Christchurch (CHCH) and 3 based in Singapore (SNG). Each captain is paid \$1000 for each block of work (even if it is only a 45 min pax). Each captain's contract guarantees he/she will be paid for 3 blocks of work even if they perform less.

The airline wants to know what shifts the captains should fly to minise the cost of covering the flights.

The airline is also curious if they can reduce the cost of their roster by using less pilots. |

 FORM FIELD ProblemFormulation FORM FIELD ComputationalModel ProblemFormulation The formulation... ComputationalModel The computational model... Results The results... Conclusions In conclusion... ExtraForExperts
Changed:
<
<
|*FORM FIELD StudentTasks*|StudentTasks|*STUDENT TASKS*

1. Add a ??? LINK ?? columnwise formulation for finding a pilot roster `flight_schedule.mod`.

What to hand in Your completed `flight_schedule.mod` file.

2. Design a system/process for generating all possible Tours of Duty (TODs). Generate the TODs to create `flight_schedule.dat`.

What to hand in A brief (less than 1 page) description of your system/process. Your `flight_schedule.dat` file.

3. Solve The Air Crew Rostering Problem. Be sure to investigate the possibility of less pilots.

What to hand in A management summary of your solution.

Extra for Experts' Tasks

1. The airline had hired another AMPL consultant to generate TODs automatically. She had almost finished before going on parental leave. She has left a multitude of files in a zip archive:

??? LINK ??? flights.zip

All the files are complete except `flight_schedule.run` (there is an incomplete version in the archive). Complete `flight_schedule.run` and run `generating_flights.run` to solve The Air Crew Rostering Problem.

What to hand in Your completed `flight_schedule.run` file. A comment on whether your solution from `generating_flights.run` agrees with your solution where you generated the TODs yourself.

|
>
>
|*FORM FIELD StudentTasks*|StudentTasks|
1. Write a columnwise formulation to solve the Airline Rostering Problem. Generate feasible shifts for your formulation using any method you choose, be sure that your method generates all possible shifts. Solve the Airline Rostering Problem and write a management summary.

Hint Using depth-first search or power sets in AMPL is difficult for this method. Using a different programming language to generate the shifts, or generating them by hand using a carefully thought out method may be easier.

What to hand in Your model file. A description of your shift generation method. Your management summary.

|

 META FILEATTACHMENT attachment="flights.jpg" attr="h" comment="" date="1203501646" name="flights.jpg" path="C:\Users\Lauren Jackson\Documents\Desktop\Desktop stuff\Twiki\Twiki images\AirCrewRostering\flights.jpg" size="44700" stream="C:\Users\Lauren Jackson\Documents\Desktop\Desktop stuff\Twiki\Twiki images\AirCrewRostering\flights.jpg" tmpFilename="" user="LaurenJackson" version="1" attachment="recurring_flights.jpg" attr="h" comment="" date="1203501673" name="recurring_flights.jpg" path="C:\Users\Lauren Jackson\Documents\Desktop\Desktop stuff\Twiki\Twiki images\AirCrewRostering\recurring_flights.jpg" size="24381" stream="C:\Users\Lauren Jackson\Documents\Desktop\Desktop stuff\Twiki\Twiki images\AirCrewRostering\recurring_flights.jpg" tmpFilename="" user="LaurenJackson" version="1"
Added:
>
>
 META FILEATTACHMENT attachment="airline_demo.xls" attr="" comment="" date="1210164051" name="airline_demo.xls" path="airline_demo.xls" size="24064" stream="airline_demo.xls" tmpFilename="" user="BaseUserMapping_333" version="1"

Copyright © 2008-2021 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding TWiki? Send feedback