Horizontal collaboration among carriers in dynamic truckload transportation
動態整車協同運輸優化運作方法研究
Student thesis: Doctoral Thesis
Author(s)
Detail(s)
Awarding Institution | |
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Award date | 2 Oct 2013 |
Link(s)
Permanent Link | https://scholars.cityu.edu.hk/en/theses/theses(858b2a5d-a78b-440f-8ade-4e2a6aa93c9a).html |
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Other link(s) | Links |
Abstract
In the contemporary transportation industry, freight carriers often need to provide
immediate transportation services so as to be able to cope with their customers'
time constraints. In the truckload transportation market, each carrier has to
manage its own trucks dynamically to fulfil requests fed to it continuously, in
accordance with tight schedules. Meanwhile, due to demand
uctuations, the
carriers are usually bombarded with excess/shortage complaints. The problem
is particularly exacerbated when, as is often the case, there is little information
on future requests and no additional resources are available. In such a situation,
prospects of cost reduction through individual order optimization become severely
limited.
In a dynamic truckload transportation environment, each carrier would like
to instantly extend its own resource portfolios in order to cope with resource
shortages. This is particularly feasible, if external, excess resources owned by other
carriers are available at that particular point in time. In this thesis, the horizontal resource collaboration approach is examined to realize further transportation cost
reductions by offering each participant carrier an opportunity to gain synergy
profits. The approach is developed from an examination of practical situations
and integrates game theory and mechanism design methods with optimization
techniques. The collaborative approach is capable of improving resource utilization
on the art of all participating carriers by balancing the required resources with the
available. The method is found to be capable of helping participating carriers
handle the dilemmas associated with instant resource shortages without losing
individual autonomy. The main research issues here involved the identification
and utilization of synergies between the resource instant utilization statuses of all
participant carriers in a dynamic transportation environment wile ensuring a fair
and efficient allocation of synergy benefits among them.
The first part of the thesis addresses the commonly faced dynamic truckload
transportation problem with capacity restriction (DTT). A noteworthy aspect of
this problem concerns truck resource shortage. If no other trucks are available,
requests beyond the carrier's own transportation capacity have to be rejected
when a resource instant shortage occurs. A mathematical programming formula
is introduced for the on-line version of the DTT problem. A column generation
algorithm, embedded with a label-correcting algorithm, has been developed to
solve the associated NP-hard problem. This formula is then used as the basis for
more complicated resource-collaboration applications, and the solutions utilized,
as benchmarks for subsequent analyses and evaluations.
The second part of the thesis proposes two resource sharing strategies among a
dominant carrier and its affiliates. Because the dominant carrier wants to maintain
market position, rather than subcontract transportation jobs, it usually prefers to hire external trucks from affiliates. In practice, external trucks should be hired by
the dominant carrier, only when resource instant shortage occurs. This makes the
new, proposed dynamic vehicle routing problem different from the more common
ones which which tend to reject excessive requests. A mathematical programming
formulation constructed by a master problem and a sub-problem is proposed to
describe the new problem. The column generation algorithm embedded with
a label-correcting algorithm helps carriers cope with new constraints as they
arise. Two resource collaboration strategies{resource collaboration on a daily basis
and resource collaboration on route basis{are drawn following a study of several
practical situations. Finally, the effectiveness of the strategies is evaluated.
The last part of the thesis discusses resource sharing among several nondominant
carriers within a dynamic truckload transportation environment. With
individual autonomy, each carrier decides whether to participate in resource
sharing before collaborative transportation starts. Resource sharing operates
in two sequential procedures: resource sharing and profit allocation. A new
collaborative and dynamic transportation problem, with due consideration of nondominant
collaborative relationships among the participating carriers is defined.
After the implementation of collaborative transportation, the solution method of
nucleolus, using a constraint generation algorithm is applied to allocate synergistic
profits.
- Trucking, Management