Flexibility in Port Selection: A Quantitative Approach Using Floating Stocks

Ports provide a number of logistical choices concerning storage, onward transport, and postponement. We investigatethe routing flexibility offered by ports with a central location with respect to the hinterland. This flexibilityis investigated using an illustrative case in which a number of alternative strategies are evaluated by means ofsimulation. Detailed cost data was used for the illustrative case. The combination of a simulation model anddetailed cost data allows us to quantify the value of the rerouting flexibility. A combination of using regionaldistribution centers and a European Distribution Center results in the lowest cost per container.supply chain;floating stock;intermodal transport;inventories;port selection

Arrival processes in port modeling: insights from a case study

This paper investigates the impact of arrival processes on the ship handling process. Two types of arrival processes are considered: controlled and uncontrolled. Simulation results show that uncontrolled arrivals of ships perform worst in terms of both ship delays and required storage capacity. Stock-controlled arrivals perform best with regard to large vessel delays and storage capacity. The combination of stock-controlled arrivals for large vessels and equidistant arrivals for barges also performs better than the uncontrolled process. Careful allocation of ships to the mooring points of a jetty further improves the efficiency.supply chain management;logistics;simulation;transportation;case study

Dietary variation and overlap in Central and Northwest European Stephanorhinus kirchbergensis and S. hemitoechus (Rhinocerotidae, Mammalia) influenced by habitat diversity

To trace the dietary evolution of the two abundant Middle to Late Pleistocene rhinoceros species Stephanorhinus kirchbergensis and Stephanorhinus hemitoechus in Europe over several climatic cycles, we examined comprehensive material of stratigraphically well-defined alaeopopulations from different regions and interglacials. Using morphometrics and mesowear analysis, these reconstructions of Stephanorhinus diets indicate that habitat diversity and interspecific competition with closely related rhinoceros species induced variation in feeding behaviour. Although anatomical features of both species suggest significantly higher dietary specializations compared to the Early to early Middle Pleistocene Stephanorhinus hundsheimensis, their mesowear signals are characteristic of a mixed feeder diet, similar to that of extant mammal species in relatively open habitats. Both species retained a degree of dietary flexibility, enabling them to survive in a range of environments. Although each of these rhinoceroses preferred different habitats, species identity alone is not sufficient to establish the real dietary traits of a Stephanorhinus palaeopopulation. As a consequence, their occurrence in a faunal assemblage alone cannot be taken to indicate a specific habitat. S. kirchbergensis and S. hemitoechus were embedded in a dynamic process of temporo-spatial replacements and interspecific differentiation of rhinoceroses in the western Palaearctic. However, dietary specialization in these Middle to Late Pleistocene European rhinoceroses was not the result of a directed time-transgressive evolution. Rather, within the range of each species' ecological tolerance, it was controlled by environmental parameters, with habitat variability as the main factor

Flexibility in Port Selection: A Quantitative Approach Using Floating Stocks

Ports provide a number of logistical choices concerning storage, onward transport, and postponement. We investigate the routing flexibility offered by ports with a central location with respect to the hinterland. This flexibility is investigated using an illustrative case in which a number of alternative strategies are evaluated by means of simulation. Detailed cost data was used for the illustrative case. The combination of a simulation model and detailed cost data allows us to quantify the value of the rerouting flexibility. A combination of using regional distribution centers and a European Distribution Center results in the lowest cost per container

Online rules for container stacking

Container stacking rules are an important factor in container terminal efficiency. In this paper, we investigate two concepts to increase efficiency and compare them to several benchmark algorithms, using a discrete-event simulation tool. The first concept is to use knowledge about container departure times, in order to limit the number of reshuffles. We stack containers leaving shortly before each other on top of each other. The second concept is the trade-off between stacking further away in the terminal versus stacking close to the exit points and accepting more reshuffles. It is concluded that even the use of imperfect or imprecise departure time information leads to significant improvements in efficiency. Minimizing the difference in departure times proved to be important. It was also found that the trade-off between stacking further away in the terminal versus stacking close by the exit points and accepting more reshuffles leads to improvements over the benchmark

ORTEC Predicts the Payback Period for its Workforce Scheduling Software

ORTEC is a Netherlands-based software company selling decision support systems based on operations research models. One of her products is HARMONY, a workforce scheduling package. We developed a model to predict its return on investment for a specific customer. The model uses a database of reference implementations to find organizations that are similar to the prospective customer’s organization. The costs and benefits have been broken down into several factors and we use this detailed information from the reference implementations to create a prediction of the return on investment for the workforce scheduling package. Using the information from the reference set allows us to move from industry-averages for potential savings to a prediction of potential savings based on the actual experiences from similar organizations. This also makes the model transparent: the outcomes can be traced to the elements that were selected from the reference set and a detailed description of the model is available. The model has been implemented successfully at ORTEC and has been of decisive value for several prospective customers. From the data analysis it appears that organizations can save a lot both on the time needed for planning and on the amount of personnel needed. In most cases, the payback time of the OR software was less than one year

Floating stocks in FMCG supply chains

In this paper we present a new distribution concept called ‘floating stocks’, which uses intermodal transport to deploy inventories in a supply chain in advance of retailer demand. Supplying part of the demand directly by road compensates the longer transit time of this transport. First an analytical comparison is made which shows that this concept has advantages in inventories over pure road and intermodal transport. Next a simulation study of a real case is made which quantifies the cost-differences in detail