68 resultados para logistics
em Aston University Research Archive
Resumo:
Physical distribution plays an imporant role in contemporary logistics management. Both satisfaction level of of customer and competitiveness of company can be enhanced if the distribution problem is solved optimally. The multi-depot vehicle routing problem (MDVRP) belongs to a practical logistics distribution problem, which consists of three critical issues: customer assignment, customer routing, and vehicle sequencing. According to the literatures, the solution approaches for the MDVRP are not satisfactory because some unrealistic assumptions were made on the first sub-problem of the MDVRP, ot the customer assignment problem. To refine the approaches, the focus of this paper is confined to this problem only. This paper formulates the customer assignment problem as a minimax-type integer linear programming model with the objective of minimizing the cycle time of the depots where setup times are explicitly considered. Since the model is proven to be MP-complete, a genetic algorithm is developed for solving the problem. The efficiency and effectiveness of the genetic algorithm are illustrated by a numerical example.
Resumo:
Purpose – The aim of this research was to ascertain the current roles and responsibilities of logistics managers in two countries, how they compare their situation with other managers and to identify the types of knowledge and experience that would assist them to develop their careers. Design/methodology/approach – This paper compares the results of a postal survey of 303 Australian and 161 British logistics managers. Findings – The study indicates that logistics managers in both countries share many similar experiences, responsibilities and perceptions of their career situations. They take considerable pride and satisfaction from these careers but recognise the need for continuing professional development in their present and future roles. Research limitations/implications – The research is limited to the respondents to the surveys. Further research in other countries including less well-developed economies would add to the generalisation of results. Practical implications – It is argued that for successful international supply chain management, there is a need to review both current and future provision in higher education and continuing professional development, in order to strengthen strategic competences and increase understanding of the significance of interdisciplinary awareness in global markets. Originality/value – This paper represents the first attempt to understand the roles, responsibilities, career pathways and future needs of logistics managers in the two countries. Its results should provide guidance to top managers for the future success of the logistics function in their organisations.
Resumo:
Purpose – The purpose of this paper is to explore the contribution of production and operations managers (POMs) and logistics managers (LMs) in improving manufacturing and service operations, comparing experiences in Australia and Britain. Design/methodology/approach – The findings are based on surveys of the two occupations in the two countries. Thus, the focus is on comparing and contrasting two strategically placed occupations within the supply chain and in two traditional manufacturing economies in developed countries, in opposing hemispheres of the world. Findings – The working lives of 254 Australian and 195 British POMs and 303 Australian and 168 British LMs are explored to see how well prepared they are for the business challenges of today, whether they see the need for changes in the ways in which they work and what satisfactions they derive from their worlds of work? Practical implications – Insights are provided for senior management into the deployment and personal and professional development needs of two key occupations within supply chain management. Originality/value – The findings from the research give fresh insights into the ways in which managers in the two areas of responsibilities in the two countries.view their worlds of work.
Resumo:
E-grocery is gradually becoming viable or a necessity for many families. Yet, most e-supermarkets are seen as providers of low value "staple" and bulky goods mainly. While each store has a large number of SKU available, these products are mainly necessity goods with low marginal value for hedonistic consumption. A need to acquire diverse products (e.g., organic), premium priced products (e.g., wine) for special occasions (e.g., anniversary, birthday), or products just for health related reasons (e.g., allergies, diabetes) are yet to be served via one-stop e-tailers. In this paper, we design a mathematical model that takes into account consumers' geo-demographics and multi-product sourcing capacity for creating critical mass and profit. Our mathematical model is a variant of Capacitated Vehicle Routing Problem with Time Windows (CVRPTW), which we extend by adding intermediate locations for trucks to meet and exchange goods. We illustrate our model for the city of Istanbul using GIS maps, and discuss its various extensions as well as managerial implications.
Resumo:
Logistics distribution network design is one of the major decision problems arising in contemporary supply chain management. The decision involves many quantitative and qualitative factors that may be conflicting in nature. This paper applies an integrated multiple criteria decision making approach to design an optimal distribution network. In the approach, the analytic hierarchy process (AHP) is used first to determine the relative importance weightings or priorities of alternative warehouses with respect to both deliverer oriented and customer oriented criteria. Then, the goal programming (GP) model incorporating the constraints of system, resource, and AHP priority is formulated to select the best set of warehouses without exceeding the limited available resources. In this paper, two commercial packages are used: Expert Choice for determining the AHP priorities of the warehouses, and LINDO for solving the GP model. © 2007 IEEE.
Resumo:
With the globalisation of world business, the border-crossing activities between organisations have substantially increased. Organisations not only need to handle supply functions, but also play a tremendous role in demand simulation through integration both inside the firm and outside with business partners and customers. Logistics has become more and more mature and sophisticated by taking on an external focus, incorporating suppliers and customers in the business processes, with all the supply chain functions integrated into a whole. By minimising the costs in the value chain or providing customised services, logistics acts as a major source of competitive advantages and profitability. To meet this goal, it would require the integration of activities to focus on customer-oriented measures. Customer service and logistics activities are a chain of interdependent activities that supplement each other to facilitate the flow of information, goods and cash within the value chain. The absence of one activity may imply some specific channels need to supplement another unit. Generally, this paper is to study the impact of corporate strategy, technology and customer satisfaction on the firm’s performance, filling the gap of good customer service effects on long-term profits. Two international delivery providers, UPS and FedEx, are studied to realise the critical success factors of express logistics.
Resumo:
Supply chains are advocated widely as being the new units for commercial competition and developments have made the sharing of supply chain wide information increasingly common. Most organisations however still make operational decisions intended to maximise local organisational performance. With improved information sharing a holistic focus for operational decisions should now be possible. The development of a pan supply chain performance framework requires an examination of the conditions under which holistic-decisions provide benefits to either the individual enterprise or the complete supply chain. This paper presents the background and supporting methodology for a study of the impact of an overall supply chain performance metric framework upon local logistics decisions and the conditions under which such a framework would improve overall supply chain performance. The methodology concludes a simulation approach using a functionally extended Gensym's e-SCOR model, together with case based triangulation, to be optimum. Copyright © 2007 Inderscience Enterprises Ltd.
Resumo:
Purpose: The purpose of this paper is to conceptualize e-business adoption and to generate understanding of the range of factors affecting the adoption process. The paper also aims at exploring the perceived impact of e-business adoption on logistics-related processes. Design/methodology/approach: Case study research, by conducting in-depth interviews in eight companies. Findings: E-business adoption is not exclusively a matter of resources. Increased e-business adoption and impact are caused by increased operational compatibility, as well as increased levels of collaboration. In terms of e-business impact this mainly refers to cycle time reductions and quality improvements, rather than direct cost reductions as reported by other authors. Research limitations/implications: The intrinsic weakness of the research method and the way concepts are operationalized limits the ability to generalize findings. Practical implications: Managers should emphasize developing their relationships with theirsuppliers/customers, in an effort to do common e-business investments, and should aim to increase their partners' commitment to the use of these applications. Originality/value: This paper provides empirical evidence from a sector where limited research efforts have taken place. Explanations can be helpful to other researchers involved in the understanding of the adoption of e-business and its impact. © Emerald Group Publishing Limited.
Resumo:
The aim of this paper is to provide an overview and an analysis of recent developments and changes in the implementation of sustainability practices by food retailers. It also aims to explore whether the sustainability measurement criteria and indicators identified in the literature can be applied in practice. A literature review identified the current trends, developments and the proposed sustainability objectives, criteria and indicators. Via case study research, we collected empirical data from four retailers. This involved both qualitative and quantitative data drawn from questionnaires and in-depth interviews with logistics directors from four retailers' distribution centres. The empirical data collected from the interviews indicate similarities in some of the characteristics of distribution centres, as well as differences. However, it was difficult to make cross-company comparisons due to the absence of benchmarks or assessments of the relative importance of each sustainability criterion and indicator. This research focused only on two sustainability objectives. Further research on other sustainability objectives is therefore required. Lessons learnt from the four case studies can be taken into consideration when developing future sustainability performance rating scales. The paper provides an in-depth analysis of sustainability in the food chain, with emphasis on food retailing. Its value lies in presenting an attempt to test in practice how a number of sustainability objectives, criteria and indicators are applied in logistics-related processes, identifying the gaps and reporting the potential difficulties.