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    <id>845</id>
    <completedYear/>
    <publishedYear/>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>reportzib</type>
    <publisherName/>
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    <completedDate>2005-01-25</completedDate>
    <publishedDate>2005-01-25</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">A Case Study of Joint Online Truck Scheduling and Inventory Management for Multiple Warehouses</title>
    <abstract language="eng">For a real world problem --- transporting pallets between warehouses in order to guarantee sufficient supply for known and additional stochastic demand --- we propose a solution approach via convex relaxation of an integer programming formulation, suitable for online optimization. The essential new element linking routing and inventory management is a convex piecewise linear cost function that is based on minimizing the expected number of pallets that still need transportation. For speed, the convex relaxation is solved approximately by a bundle approach yielding an online schedule in 5 to 12 minutes for up to 3 warehouses and 40000 articles; in contrast, computation times of state of the art LP-solvers are prohibitive for online application. In extensive numerical experiments on a real world data stream, the approximate solutions exhibit negligible loss in quality; in long term simulations the proposed method reduces the average number of pallets needing transportation due to short term demand to less than half the number observed in the data stream.</abstract>
    <identifier type="serial">05-11</identifier>
    <identifier type="opus3-id">845</identifier>
    <identifier type="urn">urn:nbn:de:0297-zib-8454</identifier>
    <enrichment key="SourceTitle">Appeared in: Operations Research 55 (2007) 733-752</enrichment>
    <author>Christoph Helmberg</author>
    <author>Stefan Röhl</author>
    <series>
      <title>ZIB-Report</title>
      <number>05-11</number>
    </series>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>convex relaxation</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>integer programming</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>stochastic demand</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>network models</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>large scale problems</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>bundle method</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>logistics</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>vehicle routing</value>
    </subject>
    <collection role="ddc" number="000">Informatik, Informationswissenschaft, allgemeine Werke</collection>
    <collection role="msc" number="90B05">Inventory, storage, reservoirs</collection>
    <collection role="msc" number="90B06">Transportation, logistics</collection>
    <collection role="msc" number="90C06">Large-scale problems</collection>
    <collection role="msc" number="90C90">Applications of mathematical programming</collection>
    <collection role="institutes" number="">ZIB Allgemein</collection>
    <file>https://opus4.kobv.de/opus4-zib/files/845/ZR-05-11.pdf</file>
    <file>https://opus4.kobv.de/opus4-zib/files/845/ZR-05-11.ps</file>
  </doc>
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