Optimal transportation and business cycles in an integrated production-inventory model with a discrete credit period

This paper considers the impact of discrete trade-credit policy depending on the purchased quantity of raw-materials on an integrated multi-cycle production inventory system of a raw-material supplier and a manufacturer in some business cycles during finite time horizon. The manufacturer collects raw-materials with offer of free transportation cost in some transportation cycles. Our objective is to get the optimal number of transportation and business cycles in two models with three cases depending on different position of the credit period with respect to production period and cycle length. Some numerical examples have been illustrated along with sensitivity analysis and managerial insights.     

Towards enhancing the last-mile delivery: An effective crowd-tasking model with scalable solutions

In urban logistics, the last-mile delivery from the warehouse to the consumer’s home has become more and more challenging with the continuous growth of E-commerce. It requires elaborate planning and scheduling to minimize the global traveling cost, but often results in unattended delivery as most consumers are away from home. In this paper, we propose an effective large-scale mobile crowd-tasking model in which a large pool of citizen workers are used to perform the last-mile delivery. To efficiently solve the model, we formulate it as a network min-cost flow problem and propose various pruning techniques that can dramatically reduce the network size. Comprehensive experiments were conducted with Singapore and Beijing datasets. The results show that our solution can support real-time delivery optimization in the large-scale mobile crowd-sourcing problem.     

Customer satisfaction and loyalty in supply chain: the role of communication

Communication between buyers and sellers is central to the supply chain philosophy. Further, the trend toward more detailed customer demands has made it even more important for firms to solicit input and feedback from their customers in order to better tailor their offerings to customer needs. Previous research suggests a strong linkage between customer satisfaction and customer loyalty. Highly satisfied customers are more loyal than less satisfied customers. Thus, it was hypothesized that firms proactively seeking information from customers should realize a “pay off” in terms of more satisfied and, subsequently, more loyal customers. A survey of buyers in the personal products industry was used to examine three methods of listening to customers. Frequency of vendor meetings with customers, formalized contact through the solicitation of feedback and/or conducting surveys, and personal visits by senior vendor managers were found to be related to customer satisfaction as well as customer loyalty.     

Cycling in a changed climate

The use of bicycle is substantially affected by the weather patterns, which is expected to change in the future as a result of climate change. It is therefore important to understand the resulting potential changes in bicycle flows in order to accommodate adaptation planning for cycling. We propose a framework to model the changes in bicycle flow in London by developing a negative binomial count-data model and by incorporating future projected weather data from downscaled global climate models, a first such approach in this area. High temporal resolution (hourly) of our model allows us to decipher changes not only on an annual basis, but also on a seasonal and daily basis. We find that there will be a modest 0.5% increase in the average annual hourly bicycle flows in London’s network due to a changed climate. The increase is primarily driven by a higher temperature due to a changed climate, although the increase is tempered due to a higher rainfall. The annual average masks the differences of impacts between seasons though – bicycle flows are expected to increase during the summer and winter months (by 1.6%), decrease during the spring (by 2%) and remain nearly unchanged during the autumn. Leisure cycling will be more affected by a changed climate, with an increase of around 7% during the weekend and holiday cycle flows in the summer months.     

Geographic Information System (GIS) Analysis of Impacts in the Tourism Area Life Cycle (TALC) of a Mediterranean Resort

Tourism in Spain has evolved from being a residual sector in the economy during the 1950s to become at present the main source of wealth in the country. The Spanish Law of Centres and National Tourist Interest Areas of 1963 created numerous new resorts on the coast whose life cycle is now over 50 years. On the Mediterranean coast, urban development and tourism model processes have been developed with major feedback to each other. In this context, it is particularly interesting to evaluate the results obtained since the decade of the 1960s in order to achieve sustainable tourism. This paper analyses a paradigmatic case study located on the Spanish Mediterranean coast. A diagnosis that explains the evolution of the life cycle tourist destination as a consumer product is carried out using geographic information system analysis of the urban plot. The mutation of the target customer, the real estate overcrowding, or the seasonality of demand will be the variables to be evaluated in order to assess the final return of the managed product. Copyright © 2015 John Wiley & Sons, Ltd.     

Optimal delivery service strategy for Internet shopping with time-dependent consumer demand

This study attempts to optimize a delivery service strategy for Internet shopping by considering time-dependent consumer demand, demand–supply interaction and consumer socioeconomic characteristics. A nonlinear mathematical programming model is formulated for solving the optimal number and duration of service cycles for discriminating strategy by maximizing profit subject to demand–supply interaction. An example is employed to demonstrate the application of the model. Results suggest that discriminating service strategy is a better strategy in response to time-dependent consumer demand than uniform strategy. Finally, the proposed model is demonstrated to yield more profit than models that do not consider variations in consumer demand or demand–supply interaction.     

Estimation of traffic density from drone-based delivery in very low level urban airspace

Driven by rising consumer demand, interest is growing in the application of autonomous unmanned aerial vehicles (drones) for the last-mile delivery of small express packages and fast-food meals in cities. To be realised, this would require the Very Low Level (VLL) urban airspace to be able to cope with high traffic densities of commercial delivery drones. The potential benefits of such novel drone-based applications are a reduction of traffic congestion in cities, lower greenhouse gas emissions and more efficient transportation operations. To help realise this concept, programs such as U-Space, the unmanned traffic management system for Europe, are developing important services such as deconfliction management and dynamic capacity management. However, for several of these services, design choices will depend on how, and how extensive they will be used. It therefore becomes important to estimate how many delivery drones would operate in a typical city. This paper aims to provide an estimate by establishing a framework to determine the traffic demand for express drone-based package delivery of five European countries. In addition, a detailed case-study is presented for determining traffic density of express package drone delivery for Paris metropolitan area in order to assess the feasibility from a user's perspective. The paper also discusses the potential of fast-food meal delivery drones compared to traditional delivery modes for Paris. Results suggest that hourly traffic densities culminating from express package and fast-food meal delivery drones will exceed today's global commercial aircraft traffic of 10,000 per day by more than six-fold for just one potential metropolitan city.     

Route reoptimization's impact on delivery efficiency

A drawback of daily reoptimization of delivery routes as a response tactic to randomly fluctuating customer demands concerns inefficiencies in actual freight deliveries to customers. Underlying these inefficiencies are route reoptimization's potentially erratic day-to-day changes in delivery routes, and hence, highly unstable route assignments for delivery vehicle drivers. This study's primary contributions are that it develops, quantifies, and models a robust metric for assessing the resulting requirements that the instability places on drivers to learn multiple routing assignments. A key research result is that regression analysis can be used to model the behavior of a metric.     

A bilevel storage pricing model for outbound containers in a dry port system

Serving as a potential solution for seaport congestion and capacity limitation, dry port development is increasingly popular in the freight transport industry. This paper pioneers the research on dry port operations by modelling the storage pricing problem for outbound containers. The interaction between a dry port and multiple shippers is modelled as a bilevel program. The optimal properties of the proposed model under certain conditions are derived analytically, from which a closed-form solution is obtained. Contrary to intuition, the increase of container delivery frequency from shippers may lead to the reduction of dry port’s profit according to model outcomes.     

Real option analysis of aircraft acquisition: A case study

This paper demonstrates that aircraft acquisition by airlines may contain a portfolio of real options (flexible strategies) embedded in the investment's life cycle, and that if airlines rely solely on the static NPV method, they are likely to underestimate the true investment value. Two real options are investigated: i) the “shutdown-restart” option (a carrier may shutdown a plane if revenues are less than costs, but restarts it if revenues are more than costs), and ii) the option to defer aircraft delivery. We quantify the values of these options in a case study of a major U.S. airline. The economic insight could help explain observed capital expenditures of airlines, and serve as a rule of thumb in evaluating capital budgeting decisions. A compound option (consisting of both the shutdown-restart and defer options) is also analyzed.     

Port system evolution in Ecuador – Migration,location splitting or specialisation?

Port facilities expand or are relocated from their original locations according to several factors, such as outgrowing a limited space or avoiding clashes of use with expanding cities. Previous spatial models such as the famous Anyport model imply a natural evolution in port systems which can in reality be complicated by issues of port governance and competition. The goal of this paper is to enrich the Anyport model with insights from port governance and the port life cycle model, focusing on strategies of port actors to avert a potential decline when the port reaches geographical or economic constraints.The empirical application explores the evolution over five decades of the port of Guayaquil, Ecuador's primary port and the second-busiest container port on the west coast of South America. In the 1990s and 2000s, port governance reform introduced devolution from the national level to local port authorities, the signing of terminal concessions to private operators and competition from other ports in the vicinity. In 2006 a new deep-water port, 85 km downriver and in a different governance jurisdiction, was proposed. Continuous legal and operational challenges stalled the construction of the new port, until it finally entered into operation in 2019. Despite this development, the existing Guayaquil port decided to go ahead with more channel dredging and to extend the existing container terminal concession for an additional 20 years in order to maintain its operations.Thus, rather than a simple port migration to deeper water based on specialisation of tasks between deep sea and feeder activities, what has emerged is a competitive situation for the same hinterland between old and new ports. The port life cycle model provides a more dynamic view than purely spatial models, highlighting governance conflicts between local and national levels, power dynamics between global carriers and port terminal operators, changes in intra- and inter-port competition and horizontal complexities arising from municipal and regional boundaries between existing and available port locations.     

Inventory control for returnable transport items in a closed-loop supply chain

An inventory control model for returnable transport items (RTI) where the manager selects the optimal length for inspection, repair, and purchase cycles is described. Repaired and newly obtained RTI are used in combination to satisfy current production requirements. Uncertain returns are incorporated into the model by determining a satisfactory safety stock level to buffer the inventory of used and repairable containers. The minimum cost solution is obtained when inspection and repair runs begin simultaneously. Cycle times are a function of the expected return rate and repairable percentage, while variability in these random assumptions affects the required safety stock.     

Integration of the cost allocation in the optimization of collaborative bundling

A model is proposed that integrates a cost allocation method – the Shapley value – into the optimization of the synchronized consolidation of transportation orders. By balancing each partner’s delivery date changes (when synchronizing) against its allocated profit, it ensures that the operational plan is acceptable by all partners. In comparison to a model that first plans and then divides the costs, this model limits expensive delivery date changes and does not systematically favor a company with a slightly higher cost of change.     

城市配送中心自有车辆规模研究

确定合理的自有车辆规模,是配送中心有效降低物流配送成本的措施之一。通过引入配送周期的概念,修正过去以天为周期计算配送中心所需车辆数的方法,从而得到能更准确反映配送中心用车情况的统计资料,在考虑内外车辆对客户服务水平的影响后,建立成本最小模型及模型求解方法,并结合算例计算出城市配送中心合理的自有车辆数。     

An integrative approach to determine store delivery patterns in grocery retailing

This article focuses on the tactical problem of selecting delivery patterns according to which grocery stores are repetitively supplied with products from different order segments by retail-owned distribution centers. The research environment considered consists of logistics processes in DCs, transportation and instore logistics. We identify dependencies on the delivery patterns selected and specify the relevant costs. These costs are reflected in the objective function of a binary selection model. Implementing and applying the model to the real case of a major European retail company yields substantial cost savings potential of 5.3%, amounting to tens of millions of euros per annum.     

Design and planning for green global supply chains under periodic review replenishment policies

We quantify the impact of jointly optimizing strategic network design and tactical inventory planning on the cost and CO₂ emissions of multi-echelon logistics networks. The obtained insights indicate that longer optimized replenishment cycles reduce a node’s transportation cost and CO₂ emissions but increase its inventory costs. Moreover, under a fixed replenishment cycle, a node’s service level increases when supplied by a satellite warehouse. Finally: (i) the costs of implementing optimal green network design decisions could be misleading if inventory planning is neglected, (ii) greening of supply chains could become expensive, (iii) current legislative CO₂ ton prices hardly influence logistics networks.     

Drivers and barriers to the adoption and diffusion of Sustainable Jet Fuel (SJF) in the U.S. Pacific Northwest

Sustainable Jet Fuel (SJF) represents an important component of the airline industry's strategy to simultaneously reduce GHG emissions while meeting a growing demand for international air travel. SJFs also have the potential to provide fuel supply diversification and security, enhance fuel price stability and provide regional/rural economic development benefits. This paper measures and ranks perceived drivers and barriers to an economically viable SJF industry in a unique U.S. region, the U.S. Pacific Northwest (PNW), through personal interviews with key aviation fuel supply chain stakeholders conducted from June to September 2015. In addition to providing a fertile arena for this first effort to systematically assess these drivers and barriers, the U.S. PNW is unique due to the region's long strategic focus on aviation innovation and its importance to the regional economy, the seminal efforts in the region to outline a path forward on SJF beginning in 2010, and the relatively small population spread over a large geographic area with a limited number of “hub” airport nodes which geographically concentrates aviation fuel demand and distribution. Nineteen stakeholder interviewees acknowledge that, in order for regional SJF adoption-diffusion to occur, airline jet fuel buyers must drive the process, particularly as they deal with greenhouse gas (GHG) emission issues and related policy considerations. Important perceived barriers to SJF industry scale-up in the U.S. PNW include the high production costs of SJF and related issues, such as fuel logistics and quality control in the transport, storage, and blending of SJFs. Perceptions around chain-of-custody issues, such as blending, tracking, and crediting of SJFs and future SJF market share projections for the year 2030 were also examined. Incorporating stakeholder input into discussions about adding blended SJF into the U.S. aviation fuel supply provides needed insight for the biofuels industry, policymakers, and researchers.     

Choice model based analysis of consumer preference for drone delivery service

It is anticipated that drones will soon be utilized for a range of applications, including delivery service. However, there has been a lack of research on consumer preference between drone delivery service and traditional delivery service. This is the first study to analyze the consumer preference for drone delivery based on a discrete choice model between the drone delivery service and traditional delivery services by truck or motorcycle. The discrete choice model is estimated using a stated preference survey, and potential consumers’ preference is analyzed for representative commodities with different price. The results show that the price and type of commodities influence consumer preference, which also depends on socio-demographic characteristics such as gender, age, and household income. Specifically, it was consistently observed in all cases that the younger the age, the higher the preference for drone delivery service. This study contributes to predicting the consumer preference for drone delivery service before real service offerings and to supporting the establishment of business strategies for companies who prepare for the new market of drone-based delivery.     

Policy momentum for the development of Taiwan's cultural creative industries

This paper contributes to the tourism and hospitality literature by examining Taiwanese policy momentum in the development of Taiwan's cultural and creative industries (CCIs). This study uses a Markov-switching model (MSM) proposed by Hamilton [1989. A new approach to the economic analysis of nonstationary time series and the business cycle. Econometrica, 57, 357–384] to analyse the influence of government policies, and the sample comprised 18 Taiwanese CCI stocks for the 2000–2014 period. The MSM decomposes policy-momentum cycles into two distinct states: high volatility and low volatility (HV and LV). The mean growth rate of the HV is 0.87% and the average growth rate of the LV is 10.37%. The state probability that will remain in the LV is 80%, and the state probability that will remain in the HV is 94%, meaning that the probability will shift from an HV (LV) to an LV (HV) is 6% (20%). The findings indicate that cultural creative industries in Taiwan have a high tendency to stay in the HV state and a low tendency to shift from an HV state to an LV state. Empirical results show that Taiwanese government policies were the main activator of development in Taiwan's CCIs and this development can continuously maintain a positive mean growth rate, even in the event of sudden economic downturns.     

Urban freight demand forecasting: A mixed quantity/delivery/vehicle-based model

The research germinates from the statement that the cities have to solve the impacts due to freight transport in order to improve their sustainability implementing sets of city logistics measures. But city logistics measures involve several actors and choice dimensions. It is therefore important to have methods and models able to assess the effectiveness of the measures to be implemented. The current models were mainly developed to simulate some aspects of urban freight transport, and are not able to forecast many impacts of implementing traffic and transportation measures at an urban scale.This paper presents a modelling approach that tries to point out the relations existing among city logistics measures, actors and choice dimensions. It comprises three model sub-systems to estimate the quantity O–D matrices by transport service type (e.g. retailer on own account or wholesaler on own account or by carrier), the delivery O–D matrices by delivery time period, and the vehicle O–D matrices according to delivery tour departure time and vehicle type.This modelling system is a multi-stage model and considers a discrete choice approach for each decisional level. It was first tested using some data collected in the inner area of Rome, including traffic counts and interviews with retailers and truck-drivers. The model estimations were also compared with the experimental ones, and quite satisfactory results were obtained.