Logistiek Biobased Economy: toekomstbeelden 2025 & agenda 2013-2017

Naast de afzetmogelijkheden van biobased producten (markten) en de technologische verwerkingsmogelijkheden, bepalen de beschikbaarheid, handel en logistiek in sterke mate de wijze waarop de biobased economy in Nederland zich zal ontwikkelen. Het is noodzakelijk in de komende jaren duurzame, economisch rendabele logistieke biomassaketens op te zetten. Op dit terrein bestaat nog veel onduidelijkheid. Het doel van het project is het vormen van: gedragen toekomstbeelden van de logistiek in de biobased economy in 2025 en een gedragen agenda met actiepunten voor 2013-2017 (ofwel waarmee moeten we starten in de eerstkomende 5 jaar om de toekomstbeelden te bereiken)

Measuring and analysing terminal capacity in East Africa: the case of the port of Dar Es Salaam

Measuring capacity and capacity utilisation at seaport terminals is essential to ensure efficient utilisation of the infra- and superstructure of the seaport. Most of the methods that have so far been used to measure capacity utilisation are not easy to comprehend for a common seaport operator. Most of the methods are also data intensive and therefore not suited for developing countries. This article attempts to use well-known standard queuing models to measure capacity utilisation in a seaport using the seaport of Dar es Salaam (Tanzania) as a case study. Historical data on terminal performance for the general cargo and the container terminal have been collected to validate the model. Based on standard queuing models it has been found that terminal capacity for both terminals is being underutilised and that, as a result, ships are being subjected to unnecessarily long waiting times; a conclusion backed up by a more detailed simulation model. Although some assumptions on which common queuing models have been derived may not hold true in practice, it is argued that standard queuing models can be used as a quick scan for evaluating seaport terminal capacity utilisation. If accurate measurement is needed, more data may need to be collected to determine the actual ship arrivals and service time distributions and develop an appropriate simulation model. The methodology developed in this article, although validated using port performance data for the port of Dar es Salaam, is directly applicable to any other seaport. © 2014 Macmillan Publishers Ltd

A method to assess multi-modal hazmat transport security vulnerabilities: Hazmat transport SVA

The suggested Hazmat transport Security Vulnerability Assessment (SVA) methodology presents a user-friendly approach to determine relative security risk levels of the different modes of hazardous freight transport (i.e., road, railway, inland waterways and pipeline transportation). First, transport routes are divided into smaller route segments. Second, likelihood scores of security-related accidents in which dangerous freight is involved and possibly causing fatalities in the surrounding population, are determined per route segment. Third, the consequences of accident scenarios (using reference products and spatial plans) are calculated in terms of the number of people within the 1% lethality distance of the accident center. Fourth, using these likelihood scores and consequence figures, transport route security risk levels are determined. Fifth, transshipment risks are considered for determining the final transport route security risk levels. This leads to a multi-modal user-friendly security threat assessment tool which can be used by policy makers as well as by industrialists (shippers or Logistics Service Providers). The generic method allows for comparing the security risk levels of the different route segments and routes of transportation of hazardous goods and for taking countermeasures from a uni-modal as well as from a multi-modal perspective. © 2012 Elsevier Ltd

An analysis of household waste management policy using system dynamics modelling

This paper analyses the Flemish household waste management policy. Based on historical data from the period 1991-2006, literature reviews and interviews, both mathematical and descriptive relationships are derived that describe Flemish waste collection, reuse, recycling and disposal behaviour. This provides insights into how gross domestic product (GDP), population and selective collection behaviour have influenced household waste production and collection over time. These relationships are used to model the dynamic relationships underlying household waste management in Flanders by using a system dynamics (SD) modelling approach. Where most SD models in literature are conceptual and descriptive, in the present study a real-life case with both correlational and descriptive relationships was modelled for Flanders, a European region with an outstanding waste management track record. This model was used to evaluate the current Flemish household waste management policy based on the principles of the waste hierarchy, also referred as the Lansink ranking. The results show that Flemish household waste targets up to 2015 can be achieved by the current waste policy measures. It also shows the sensitivity of some key policy parameters such as prevention and reuse. Given the general nature of the model and its limited data requirements, the authors believe that the approach implemented in this model can also assist waste policy makers in other regions or countries to meet their policy targets by simulating the effect of their current and potential household waste policy measures. © The Author(s) 2010

A matheuristic for aggregate production-distribution planning with shared resources

This paper discusses the aggregate production-distribution problem for a manufacturer of plastic products that are produced using injection moulding. For each product, only a single mould is available, but by exchanging moulds between plants, it is possible to produce any product at any plant. This mould sharing offers opportunities for cost savings but complicates the aggregate production-distribution planning. We present mixed integer linear programming formulations for this planning problem, and a matheuristic solution approach based on these models. The main goal of this aggregate planning tool is to quantify the opportunities that mould sharing offers to the plastics manufacturer. Computational experiments based on a real-life dataset confirm that mould sharing can reduce the production-distribution total cost with about 10%, and that the suggested matheuristic is capable of generating solutions that capture most of this significant savings potential. © 2013 Elsevier B.V

An empirical investigation of Lead-time reduction in purchasing groups: evidence from SMEs

This paper aims to empirically examine the impact of horizontal cooperation in purchasing on the lead times of the orders from suppliers. Two groups of SMEs participating in purchasing groups were investigated for a ninemonth period of data collection. However, for one of the groups involved in cooperative transportation of the purchased goods, total lead-time was measured, and further analysis was conducted. The outcomes of this study show that firms involved in purchasing consortia face significant shorter lead times up to 45%. Meanwhile, the lead times for the firms cooperating in both purchasing and transportation tasks were shorter than for the other group. Additional managerial conclusions and unique contributions are drawn. Copyright © 2012 Inderscience Enterprises Ltd

The impact of lead time reliability in freight transport: A logistics assessment of transport economics findings

This paper considers speed and reliability, measured by the average and variance of the lead time, to examine the relevance of the latter variable on inventory costs. By using a flexible simulation framework, it is shown that reducing variability does not necessarily reduce costs and might in fact increase the costs of safety stock, depending on the shape of the demand distribution during lead time and the targeted service level. This offers a novel explanation for the wide variety of value of reliability figures obtained in empirical transport economics research. © 2012 Elsevier Ltd