Mixed fleet dispatching in truckload relay network design optimization

Regenerator Location Problem and survivable extensions: A hub covering location perspective

“…The relay network design problem in freight transportation systems as studied in Ali et al (2002) is almost identical with RLP. The hub-and-spoke aspect of relay networks has originated with the work of Taha and Taylor (1994) and has been adopted as an alternative dispatching method for TL transportation in order to alleviate the common driver retention problem in several studies (please see Taylor et al (1999), Ali et al (2002), Uster and Maheshwari (2013), Uster and Kewcharoenwong (2011), Konak (2012), Vergara and Root (2013) and the references therein). Though relay networks and hub-and-spoke networks (not necessarily complete hub networks) are very similar, there are operational limitations such as circuity, distances between relay points, load balance at relay points, and number of handlings from origin to destination that are specific to TL transportation in relay networks.…”

“…Though relay networks and hub-and-spoke networks (not necessarily complete hub networks) are very similar, there are operational limitations such as circuity, distances between relay points, load balance at relay points, and number of handlings from origin to destination that are specific to TL transportation in relay networks. Incorporating some of these limitations within an exact solution methodology for relay network designs has been the challenge in works of Uster and Maheshwari (2013), Uster and Kewcharoenwong (2011) and Vergara and Root (2013) who manage to achieve optimal or near-optimal results for moderate sized problem instances. Our RLP designs from a relay network perspective inherently satisfy the spatial requirements among the relay points though overlook other requirements.…”

Delivery and Pick-Up Problem Transportation - Milk Run and Conventional Systems

“…That is, the automaker purchases FOB (free on board). Transport costs therefore have to be paid by the automaker (VERGARA; ROOT, 2013;TING;. With the Milk Run system, the parts will be transported to the automaker in the right amount and only when they are ordered.…”

“…Therefore, if the batch size is large, a vehicle with higher capacity will be necessary (in weight and volume) compared to a small acquisition batch size (Q3) for the system called Conventional. Thus, it would directly influence the total cost of the vehicle, as the fixed and variable costs of a vehicle with higher capacity are higher than the fixed and variable costs of a lower capacity vehicle (VERGARA; ROOT, 2013;TING;.…”

“…However, the commitment between the parts (assembler and supplier) tends to increase, as well as the information flow, optimizing the process of ordering supplies which should reduce the administrative costs of receiving materials. Moreover, depending on the financial importance of the item to be ordered by the automaker (within ABC classification), collection of a component or part within the category "C" several times a week would not be justified, because the cost of invoice in each collection could be higher than keeping that item in stock for a few days (VERGARA; ROOT, 2013;WIENGARTEN et al, 2013;TING;YANG et al, 2013;EGBELU;CHANG, 2013;ZHANG, 2013;BENNET;KLUG, 2012). In the Milk Run system unit cost of purchase (Cunit) is lower compared to the conventional system, regardless of the quantity purchased.…”