Customer Locations Research Articles

AN ALGORITHM FOR THE GENERALIZED VEHICLE ROUTING PROBLEM WITH BACKHAULING

The Vehicle Routing Problem with Backhauling deals with the supply of finished goods from a depot to a number of delivery points, and picking up returnable items and bringing them back to the depot using a fleet of trucks. Traditionally, the objective of the problem has been to determine the truck routes such that the total number of trucks and/or the total distance traveled/total route cost are minimized. Most of the papers available in the literature in this connection deal with problems where the linehaul (having a demand for finished goods) and backhaul (having items to be returned to the depot) customers are different, and a customer may be visited by at most one truck limiting demand and returns at a location by the capacity of the truck. In this paper, we allow the linehaul and backhaul customers to be the same leading to simultaneous delivery and pickup at a customer location, and also there is no restriction on the quantity demanded at (to be returned from) a customer location. As such a customer may be visited by more than one truck and more than once by the same truck. We developed a Mixed Integer Linear programming (MILP) formulation of the problem and a route construction heuristic. The heuristic averaged 80 ms for 110 problems tested, and in 78 of them the heuristic costs were either equal to the optimal costs or at most equal to the upper bounds on the optimal costs obtained after running the optimization package for 30 min. Optimal solutions were obtained for 28 problems at an average time of 295 ms. The heuristic could match the optimal solutions for 22 of these problems at an average time of 71 ms.

Retail network planning — Achieving competitive advantage through geographical analysis

Retail businesses have long recognised that understanding and improving overall performance starts with analysis at the micro or local market level. Attention has been focused on an increasing body of evidence that demonstrates market share can vary significantly from one local market to another. Added to this realisation, there is often a pressing need to provide high-quality information to support new site development, outlet closures and mergers, where the location of customers and competitor outlets plays a crucial role in determining the outcome of decisions. Using the right tools and techniques, it is possible to predict these outcomes with increasing levels of reliability.

Reliability of Plug Power GenSys™ fuel cell systems

The pace at which fuel cell systems are widely adopted by the marketplace will be determined primarily by two factors: (1) the rate at which system cost decreases and (2) the rate at which system reliability increases. This paper describes the field reliability and its improvement through a combination of software and hardware changes of Plug Power's GenSys™ fleet of 5 kWe (plus up to 9 kW of thermal energy) proton exchange membrane (PEM) fuel cell systems. Plug Power has shipped more than 300 of these systems to more than 50 customer locations in more than 10 countries. This fleet is of sufficient size, and has been operating for a sufficient length of time, to develop statistically significant observations of system reliability. Nondimensionalized probability plots of PEM stack lifetime in field units are presented, and a series of system-level changes are described that have increased PEM stack life by about a factor of 4. Nondimensionalized, system-level reliability statistics are also presented for the installed fleet. Pareto charts describing the top causes for system failures in the field are shown, and the general methodologies for improving system-level reliability are discussed.

The Role of HAPs in Supporting Multimedia Broadcast and Multicast Services in Terrestrial-Satellite Integrated Systems

New-generation telecommunications systems are expected to meet the rising user exigencies of mobility and ubiquitous access to multimedia services. As a consequence, 3GPP consortium has introduced the Multimedia Broadcast and Multicast Service (MBMS) concept into 3G/beyond-3G networks. Supporting MBMS in next generation hybrid wireless platforms becomes a challenging issue due to high traffic load deriving from both signaling message exchange and data transmission between multicast sources (BM-SC) and end users. Therefore, in this context, key research issues are surely: effective exploitation of the limited radio spectrums available, coordination of users accessing radio resources, as well as provisioning of desired QoS guarantees. Given the high mobility profiles typical of UMTS users, it clearly appears that the cited target performance can only be achieved through networking solutions based on an overlapped terrestrial-HAP-satellite coverage. An inter-working scenario where HAPs operate in synergy with the UMTS terrestrial and satellite segments seems to be the most promising solution to provide mobile users with MBMS services. Our work, dealing with architectural design options, takes into account many metrics relevant to aspects, such as: frequency allocation, costs in terms of resource utilization, signaling traffic load, number and location of customers, reliability, possible retransmission paths, user mobility, and QoS.

Sysco Corp.

AbstractRetail ‐ Food & Beverage (MIC: 5.3 SIC: 5141 NAIC:424410)Sysco is engaged in the marketing and distribution of food and related products to the foodservice or “food‐prepared‐away‐from‐home” industry. These services are performed for approximately 400,000 customers from 150 distribution facilities located throughout U.S. and Canada. Broadline segment distributes a full line of food products and non‐food products to both traditional and chain restaurant customers. SYGMA segment distributes a full line of food products and non‐food products to certain chain restaurant customer locations. “Other” segment includes Co.'s specialty produce, custom‐cut meat, Asian cuisine foodservice and lodging industry products segments.

Sysco Corp.

Mergent's Dividend AchieversVolume 2, Issue 2 p. 267-267 U.S. Company Report Sysco Corp.† First published: 22 April 2005 https://doi.org/10.1002/div.2438 † Contact: : Richard J Schnieders — Chmn., C.E.O. Address: : 1390 Enclave Parkway, Houston, TX 77077-2099 Web Site: : www.sysco.com AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat Abstract Retail - Food & Beverage (MIC: 5.3 SIC: 141 NAIC: 24410) Sysco is engaged in the marketing and distribution of food and related products to the foodservice or “food-prepared-away-from-home” industry. These services are performed for approximately 400,000 customers from 150 distribution facilities located throughout U.S. and Canada. Breadline segment distributes a full line of food products and non-food products to both traditional and chain restaurant customers. SYGMA segment distributes a full line of food products and non-food products to certain chain restaurant customer locations. “Other” segment includes Co.'s specialty produce, custom-cut meat, Asian cuisine foodservice and lodging industry products segments. Volume2, Issue2Spring 2005Pages 267-267 RelatedInformation

The A Priori Dynamic Traveling Salesman Problem with Time Windows

In this paper we examine the traveling saleman problem with time windows for various degrees of dynamism. In contrast to the static problem, where the dispatcher can plan ahead, in the dynamic version, part or all of the necessary information becomes available only during the day of operation. We seek to minimize lateness and examine the impact of this criterion choice on the distance traveled. Our focus on lateness is motivated by the problem faced by overnight mail service providers. We propose a real-time solution method that requires the vehicle, when idle, to wait at the current customer location until it can service another customer without being early. In addition, we develop several enhanced versions of this method that may reposition the vehicle at a location different from that of the current customer based on a priori information on future requests. The results we obtained on both randomly generated data and on a real-world case study indicate that all policies proved capable of significantly reducing lateness. Our results also show that this can be accomplished with only small distance increases. The basic policy outperformed the other methods primarily when lateness and distance were equally minimized and proved very robust in all environments studied. When only lateness was considered, the policy to reposition the vehicle at a location near the current customer generally provided the largest reductions in average lateness and the number of late customers. It also produced the least extra distance to be traveled among the relocation policies.

Two-echelon spare parts inventory system subject to a service constraint

In this paper, we consider a spare parts inventory problem faced by a manufacturer of electronic machines with expensive parts that are located at various customer locations. The parts fail infrequently according to a Poisson process. To serve customers when a failure occurs, the manufacturer operates a central warehouse and many field depots that stock spare parts. The central warehouse acts as a repair facility and replenishes stock at the field depots. There is a centralized decision-maker who manages the inventory in both the central warehouse and the field depots. We develop a continuous review, base stock policy for this two-echelon, multi-item spare parts inventory system. We formulate a model to minimize the system-wide inventory cost subject to a response time constraint at each field depot. We present an efficient heuristic algorithm and study its computational effectiveness.

Sysco Corp.

AbstractRetail‐Food & Beverage (MIC: 5.3 SIC: 5141 NAIC:424410)Sysco, acting through its subsidiaries and divisions, is a distributor of food and food related products to the foodservice or “food‐prepared‐away‐from‐home” industry. Co. provides its products and services to restaurants, healthcare and educational facilities, lodging establishments and other foodservice customers. Co.'s Broadline companies segment distributes food products and non‐food products to both Co.'s traditional and chain restaurant customers. SYGMA companies distribute food products and non‐food products to some of Co.'s chain restaurant customer locations.

Inventory Positioning in Multiple Product Supply Chains

In this paper we address the problem of inventory positioning, i.e., the determination of the supply chain node where inventory should be held, to minimize holding costs given a pre-specified order fill rate. A single-echelon inventory system with multiple products models the problem. The value of inventory is assumed to be an increasing function of the amount of processing performed at upstream nodes, while achieved fill-rates are dependent on the distance or time between the inventory storage and customer locations. We propose a novel analytical approach to solve the problem for the case of normally distributed demand that is based on iterative calculations of inventory holding costs at the various potential inventory locations.

Taxi Dispatch System Based on Current Demands and Real-Time Traffic Conditions

The existing taxi dispatch system that taxi operators in Singapore use to handle current bookings was studied. This dispatch system adopts the Global Positioning System and is based on the nearest-coordinate method: the taxi assigned for each booking is the one with the shortest, direct, straight-line distance to the customer location. However, the taxi assigned under this system often is not capable of reaching the customer in the shortest time possible. An alternative dispatch system is proposed, whereby the dispatch of taxis is determined by real-time traffic conditions. In the proposed system, the taxi assigned the booking job is the one with the shortest time path, reaching the customer in the shortest time. This dispatch ensures that customers are served within the shortest period of time and increases customer satisfaction. The effectiveness of both the existing and the proposed dispatch systems is investigated through computer simulations. The results from a simulation model of the Singapore central business district network are presented and analyzed. Data from the simulations show that the proposed dispatch system is capable of being more efficient in dispatching taxis more quickly and leads to more than 50% reductions in passenger pickup times and average travel distances. A more efficient dispatch system would result in higher standards of customer service and a more organized taxi fleet to meet customer demands better.

Facility location models for immobile servers with stochastic demand

AbstractThis paper presents several models for the location of facilities subject to congestion. Motivated by applications to locating servers in communication networks and automatic teller machines in bank systems, these models are developed for situations in which immobile service facilities are congested by stochastic demand originating from nearby customer locations. We consider this problem from three different perspectives, that of (i) the service provider (wishing to limit costs of setup and operating servers), (ii) the customers (wishing to limit costs of accessing and waiting for service), and (iii) both the service provider and the customers combined. In all cases, a minimum level of service quality is ensured by imposing an upper bound on the server utilization rate at a service facility. The latter two perspectives also incorporate queueing delay costs as part of the objective. Some cases are amenable to an optimal solution. For those cases that are more challenging, we either propose heuristic procedures to find good solutions or establish equivalence to other well‐studied facility location problems. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004.

(Re)Solving Space and Time: Fulfilment Issues in Online Grocery Retailing

There has been much hype and speculation in the media and in academe on the vitality and future of the ‘Internet economy’. In this paper the author uses case studies from Britain, Canada, New Zealand and the United States to assess the strengths and weaknesses of online grocery retailers, from national chain stores pursuing a ‘bricks and clicks' strategy to ‘pure-play’ startups. He argues that delivering groceries via the Internet to customer doorsteps requires ways of solving space and time that are markedly different from previous trends in food retail logistics. He holds that solving problems of space management creates problems in the management of time and vice versa. In particular, ‘e-tailers’ struggle with fulfilment costs and logistics, and have attempted to manage customers' time and locations to reduce these costs. Store-based operations may be best suited for short-term profitability (or loss minimisation), whereas warehouse-based fulfilment may hold future promise of greater efficiency and flexibility. The author suggests that online organic home delivery may be the most successful type of online food retailer, for its size, given greater customer commitment and problems with store-based supply of organic food.

How New Product Introductions Affect Sales Management Strategy: The Impact of Type of “Newness” of the New Product

How do firms adjust sales management strategy for new product launch? Does sales management strategy change more radically for different types of new products such as new‐to‐the‐world products versus product revisions? Because firms introducing a new product rely considerably on their sales force in the product launch effort, the types and degree of changes made in managing the selling effort are important issues. Past studies have demonstrated that firms make substantial adjustments in their sales management strategy when they introduce a new product. This study expands on previous investigations by examining whether sales management strategy changes are conditioned by the type of newness of the new product to the market and to the firm.Australian sales managers were asked to respond to a mail questionnaire concerning pre‐ and post‐new product launch sales management activities. Three groups of firms were compared: (1) those with new‐to‐the‐market and new‐to‐the‐firm products (i.e., new‐to‐the‐world products); (2) those with products new to the firm but not new to the market; and (3) those with products that are revisions to the firm and not new to the market. The study finds that firms do not make the most adjustments for products with the greatest degree of market newness—the new‐to‐the‐world types of products—except in the sales management strategy categories of compensation and supervision. In the other sales management strategy categories defined for study—organization, training, quotas and goals, and sales support as well as for all categories in the aggregate—sales management strategy changes were greatest in incidence, as measured both by the percent of firms making changes and the average number of changes per firm, when the new product was new to the firm but not new to the market.These results suggest that, because different types of new products face different competitive environments, there may be greater incentive for a not‐new‐to‐the‐market new‐to‐the‐firm product to make changes in sales strategy. Uncertainties about market size and customer location with new‐to‐the‐world products may limit the understanding of what changes to make in the strategy categories of quotas and territories. Similarly, uncertainties about product use and customer acceptance of new‐to‐the‐world products may limit the development of training and sales support materials by these firms. Instead, these firms may rely more on compensation and supervision to direct sales efforts for new‐to‐the‐world products. However, observing the market experience and performance of the first‐to‐market product can benefit firms launching a not‐new‐to‐market and new‐to‐the‐firm product, allowing them to rely more on strategy changes in training, sales support materials, organizational adjustments such as redeployments, and quotas.

An Improved Branch-and-Cut Algorithm for the Capacitated Vehicle Routing Problem

The capacitated vehicle routing problem (CVRP) deals with the distribution of a single commodity from a centralized depot to a number of specified customer locations with known demands. The CVRP considered in this paper assumes common vehicle capacity, fixed or variable number of vehicles, and an objective to minimize the total distance traveled by all the vehicles. This paper develops several new cutting planes for this problem, and uses them in an exact branch-and-cut algorithm. Two of the new cutting planes are based on a specified structure of an optimal solution and its existence. Computational results are reported for 1,650 simulated Euclidean problems as well as 24 standard literature test problems; solved problems range in size from 15–100 customers. A comparative analysis demonstrates the significant computational benefit of the proposed method.

Modelling and solving central cycle problems with integer programming

We consider the problem of identifying a central subgraph of a given simple connected graph. The case where the subgraph comprises a discrete set of vertices is well known. However, the concept of eccentricity can be extended to connected subgraphs such as: paths, trees and cycles. Methods have been reported which deal with the requirement that the subgraph is a path or a constrained tree. We extend this work to the case where the subgraph is required to be a cycle. We report on computational experience with integer programming models of the problems of identifying cycle centres, cycle medians and cycle centroids. The problems have applications in facilities location, particularly the location of emergency facilities, and service facilities. Scope and purpose This paper looks at ways of locating a circuit (cycle), such as an inner city rail link or a delivery or collection route, so that all customers wanting to use the link or be near to the delivery or collection route have minimal inconvenience in reaching it. The problem is looked at from a fairly abstract point of view and ways of modelling different types of cycles are considered. These cycles will represent sets of facilities located in a circular structure. Practical applications of the model are considered and discussed. Integer programming models are built of three different cycle problems—the cycle centre problem, the cycle median problem and the cycle centroid problem. The cycle centre problem corresponds to locating a cycle of facilities so the furthest distance travelled by any customer is minimised. The cycle median problem locates the cycle such that it minimises the total distance travelled by all customers and the cycle centroid problem essentially locates the cycle in order to minimise all distances travelled by customers. The models are then tested out on instances of networks that are generated to simulate realistic features of customer location and optimal solutions (optimal cycles) are sought and obtained. Computational experience is reported but it becomes clear that although the exact methods perform adequately on small to medium sized networks they cannot easily solve large instances of the models. For large instances approximate solutions would need to be the fallback position.

Multi-attribute label matching algorithms for vehicle routing problems with time windows and backhauls

We consider the class of vehicle routing problems with backhauls and time window constraints. Our motivating application is the land transportation of air-cargo freight forwarders, which requires fast solution times and the ability to handle various operational issues such as heterogeneous vehicles, multiple trips per vehicle, and penalty for early arrival at customer sites. We formulate the problem in the framework of label matching where the labels have multiple attributes representing the states of vehicles at customer locations or possible routes that vehicles may continue to cover. Two optimization-based heuristics are developed. Experimental tests on random problems and real data show that the methods can produce quality solutions quickly and are flexible in incorporating complex constraints.

Investigating the Effects and Profitability of Urban Co-operative Freight Transport Systems Considering Customers Location and Systems Type

This paper focuses on the effects and profitability of urban co-operative freight transport systems. Forecasted VRPTW based mathematical models were used for investigating the influence of the location of customers and different types of co-operative freight transport systems on the effects and financial viability of such systems. Applications of the models to an urban goods delivery revealed that co-operative freight transport systems cannot be profitable if the location of customers is widely dispersed within-urban areas and considerable benefits can be gained by implementing carriers-led co-operative freight transport systems without the leadership of public sector.

The latest in virtual private networks: part I

Virtual private networks (VPNs) are discrete network entities configured and operated over a shared network infrastructure. An intranet is a VPN in which all the sites (the customer locations that are part of a VPN) belong to a single organization. An extranet is a VPN with two or more organizations wishing to share (some) information. In the business world, VPNs let corporate locations share information over the Internet. VPN technology is being extended to the home office, providing telecommuters with the networking security and performance commensurate with that available at the office. Service providers are looking at their geographic footprints and their network routing expertise to create and deliver new revenue-generating VPN services. Looking ahead, these provider-provisioned and managed VPNs are intended to emulate whatever local- or wide-area network connectivity customers desire.

Household Switching Behavior at Depository Institutions: Evidence from Survey Data

This article presents descriptive findings from new survey data on households' decisions to change or remain with their providers of checking or savings accounts. The data show that the distribution of household tenure is wide, and that about a third of households have never changed depository institutions. The primary reason reported for changing banks is a household relocation; other reasons are customer service and price factors. Customer service and location are the most frequently cited reasons for remaining with a bank. The importance of location and mobility supports previous survey evidence that the local area is the appropriate market for competitive analysis in banking. The findings presented here are consistent with earlier studies showing that population migration increases competitive pressure on firms and therefore should mitigate the anticompetitive effects of bank mergers.