liu.seSearch for publications in DiVA
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Decision support tools for dynamic fleet management: applications in airline planning and ambulance logistics
Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.ORCID iD: 0000-0002-5868-2388
2005 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

In this work, decision support tools for dynamic fleet management problems are developed. The operational management tasks include dispatching, supervising and sometimes reconstructing the vehicle schedule. These tasks are often complex, while the time available to complete them is short. Therefore, decision support tools assisting the controller can be of great service.

Two studies on dynamic fleet management problems are presented. The first concerns airline planning and the problem of how to handle schedule perturbations. The second study is within the field of ambulance logistics, with focus on operational ambulance control.

For an airline, the flight perturbation problem arises when it is impossible to continue executing the original aircraft schedule, e.g. due to an aircraft breakdown. The flight controller then has to decide whether some flights have to be delayed or cancelled, or perhaps flights have to be reassigned to new aircraft. This is done in order to find an attainable, cost effective solution, where the airline can continue to serve the passengers. In this work, a decision support tool that can repair the aircraft schedule is suggested. The tool is based on a multicommodity network flow model with side constraints. A number of different solution strategies are suggested for the model, including heuristics based on column generation and meta heuristics utilizing path relinking. Computational tests show that several of the solution algorithms find near optimal solutions within a few seconds.

Ambulance logistics comprises most aspects of managing an efficient ambulance health care. This involves both emergency medical services and patient transportations. Controlling a fleet of ambulances includes deciding which ambulance to dispatch to a call. The controller also has to ensure that most or all parts of the area of responsibility can be reached by an ambulance in a short time. This is referred to as maintaining an adequate level of preparedness in the area. In this work, a way of calculating the preparedness is presented. It is incorporated into a number of decision support tools, including a dispatch tool and a relocation tool. The dispatch tool can suggest which ambulance to assign to a new call. The relocation tool suggests a way of relocating the ambulances, i.e. sending them to new locations, to increase the level of preparedness in the area. A simulation tool is also developed and used to study the effect of dynamically relocating ambulances. Furthermore, it is used to test if new locations for the ambulance stations will affect the waiting periods for the patients. The results show that the decision support tools have a positive effect on the system performance.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press , 2005. , 64 p.
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 942
National Category
Engineering and Technology
Identifiers
URN: urn:nbn:se:liu:diva-28405Local ID: 13541ISBN: 91-85297-91-7 (print)OAI: oai:DiVA.org:liu-28405DiVA: diva2:249211
Public defence
2005-05-20, K3, Kåkenhus, Campus Norrköping, Linköpings universitet, Norrköping, 13:15 (English)
Opponent
Available from: 2009-10-09 Created: 2009-10-09 Last updated: 2013-10-15Bibliographically approved
List of papers
1. The flight perturbation problem
Open this publication in new window or tab >>The flight perturbation problem
2004 (English)In: Transportation planning and technology (Print), ISSN 0308-1060, Vol. 27, no 2, 91-117 p.Article in journal (Refereed) Published
Abstract [en]

Airlines spend considerable time, effort and financial resources on planning. It is essential to create a competitive timetable and construct a fleet and a crew schedule that utilizes these resources to the maximum. Unfortunately, it is all too common that an airline is faced with the necessity of reconstructing their schedules due to some unforeseen event, for example an aircraft breakdown or a crew member that is indisposed. In this paper, an application that can help airlines solve the complex problem of reconstructing aircraft schedules is presented. A mixed integer multicommodity flow model with side constraints is developed and further reformulated into a set packing model using the Dantzig—Wolfe decomposition. Cancellations, delays and aircraft swaps are used to resolve the perturbation, and the model ensures that the schedule returns to normal within a certain time. Two column generation schemes for heuristically solving the model are tested on real problem data obtained from a Swedish domestic airline. The computational tests show that the application is capable of presenting high quality solutions in a few seconds and therefore can be used as a dynamic decision support tool by the airlines.

Keyword
Airline operations; Scheduling; Optimization; Perturbations; Dantzig—Wolfe decomposition
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-17061 (URN)10.1080/0308106042000218195 (DOI)
Note
This is an electronic version of an article published in:Tobias Andersson Granberg and Peter Värbrand, The flight perturbation problem, 2004, Transportation planning and technology, (27), 2, 91-117.Transportation planning and technology is available online at informaworldTM: http://dx.doi.org/10.1080/0308106042000218195Copyright: Taylor & Francishttp://www.tandf.co.uk/journals/default.aspAvailable from: 2009-03-04 Created: 2009-03-04 Last updated: 2013-10-15Bibliographically approved
2. Solving the flight perturbation problem with meta heuristics
Open this publication in new window or tab >>Solving the flight perturbation problem with meta heuristics
2006 (English)In: Journal of Heuristics, ISSN 1381-1231, Vol. 12, no 1-2, 37-53 p.Article in journal (Refereed) Published
Abstract [en]

When there is a perturbation in a carefully constructed aircraft schedule, e.g. an aircraft breakdown, it is important to minimize the negative consequences of this disturbance. Here, a tabu search and a simulated annealing approach to the flight perturbation problem are presented. The heuristics use a tree-search algorithm to find new schedules for the aircraft, and utilize a path relinking strategy to explore paths between structurally different solutions. The computational results indicate that the solution strategies, especially the tabu search, can be successfully used to solve the flight perturbation problem.

Keyword
Aircraft recovery - Irregular operations - Operational airline scheduling - Simulated annealing - Tabu search - Path relinking
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-17062 (URN)10.1007/s10732-006-4833-4 (DOI)
Note
The original publication is available at www.springerlink.com: Tobias Andersson Granberg, Solving the flight perturbation problem with meta heuristics, 2006, Journal of Heuristics, (12), 1-2, 37-53. http://dx.doi.org/10.1007/s10732-006-4833-4 Copyright: Springer Science Business Media http://www.springerlink.com/ Available from: 2009-03-04 Created: 2009-03-04 Last updated: 2013-10-15
3. Decision support for efficient ambulance logistics
Open this publication in new window or tab >>Decision support for efficient ambulance logistics
2005 (English)Report (Other academic)
Abstract [en]

Ambulance logistics comprises everything that has to do with managing an efficient ambulance health care, which includes both emergency medical services and patient transportations. In this work, ambulance logistics is defined and discussed using the Swedish public service enterprise SOS Alarm as a basis. A number of ways of improving the ambulance logistic service provided by SOS Alarm is identified. Work that has been performed in two of the nine identified areas is described in more detail. In both of these two areas, the main improvement lies in the development of decision support tools for the ambulance dispatchers. The tools that are developed are a preparedness calculator, an ambulance dispatch tool a relocation tool and a simulation tool.

Place, publisher, year, edition, pages
Linköping: Department of Science and Technology (ITN), Campus Norrköping, Linköping University, 2005. 15 p.
Series
ITN research report, ISSN 1650-2612 ; 1
Keyword
Ambulance logistics, Preparedness, Dispatch, Relocation, Optimization, Simulation
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-85908 (URN)
Available from: 2012-12-03 Created: 2012-12-03 Last updated: 2012-12-03
4. Quantifying the preparedness for efficient ambulance logistics
Open this publication in new window or tab >>Quantifying the preparedness for efficient ambulance logistics
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Preparedness is an important concept in ambulance logistics. It is a way of evaluating the ability to serve potential patients with ambulances in a swift and efficient manner. Here, a way of calculating the preparedness for different parts of a geographical area is presented. The developed measure is calibrated for use in the county of Stockholm in Sweden. Different areas of application for the measure are discussed in strategic, tactical and operational ambulance planning. Specifically, a mathematical model for ambulance station location, based on the preparedness measure, is developed and solved using a simulated annealing heuristic. A new set of locations, obtained from the model, is compared to the existing locations by simulating the ambulance operations. The results show that the new locations have a positive effect on the patient waiting periods.

Keyword
Preparedness, Ambulance Logistics, Location Analysis, Optimization, Transportation
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-85912 (URN)
Available from: 2012-12-03 Created: 2012-12-03 Last updated: 2012-12-03
5. Decision support tools for ambulance dispatch and relocation
Open this publication in new window or tab >>Decision support tools for ambulance dispatch and relocation
2007 (English)In: Journal of the Operational Research Society, ISSN 0160-5682, Vol. 58, 195-201 p.Article in journal (Refereed) Published
Abstract [en]

In this paper, the development of decision support tools for dynamic ambulance relocation and automatic ambulance dispatching is described. The ambulance dispatch problem is to choose which ambulance to send to a patient. The dynamic ambulance relocation problem occurs in the operational control of ambulances. The objective is to find new locations for some of the ambulances, to increase the preparedness in the area of responsibility. Preparedness is a way of evaluating the ability to serve potential patients with ambulances now and in the future. Computational tests using a simulation model show that the tools are beneficial in reducing the waiting periods for the patients.

Keyword
health, logistics, optimisation, simulation, heuristics
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-17063 (URN)10.1057/palgrave.jors.2602174 (DOI)
Note
This is a post-peer-review, pre-copyedit version of an article published in Journal of the Operational Research Society. The definitive publisher-authenticated version: Tobias Andersson Granberg and Peter Värbrand, Decision support tools for ambulance dispatch and relocation, 2007, Journal of the Operational Research Society, (58), 195-201.is available online at: http://dx.doi.org/10.1057/palgrave.jors.2602174Copyright: Palgrave Macmillanhttp://www.palgrave-journals.com/pal/index.htmlAvailable from: 2009-03-05 Created: 2009-03-04 Last updated: 2013-10-15Bibliographically approved

Open Access in DiVA

No full text

Authority records BETA

Andersson, Tobias

Search in DiVA

By author/editor
Andersson, Tobias
By organisation
Department of Science and TechnologyThe Institute of Technology
Engineering and Technology

Search outside of DiVA

GoogleGoogle Scholar

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 4470 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf