Download or read book Heuristics and Exact Algorithms for Synchronized Pickup and Delivery Problems written by Imadeddine Aziez and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In today's challenging and competitive global business environment, supply chains have become more complex and sensitive due to their dependence on constantly changing customer demands. Creating value for customers does not always refer to the quality or quantity of the product, it also refers to the availability of the product on time at the requested location. Leveraging a supply chain to provide high value to customers cannot be possible without effectively organized transportation. A better delivery service increases the availability of products to fulfill the demand of customers. Therefore, business practitioners consider it a very important factor in creating value for customers. Transportation is one of the key components in the entire supply chain, it has a critical role in maintaining a robust and resilient supply chain. Moreover, an efficient transportation network helps businesses to reduce operating costs, increase service levels, and gain a clear advantage over the competition. This increases research interest focused on transportation operations management. Throughout this research, we are interested in pickup and delivery problems (PDPs) which are a generalization of the classical vehicle routing problem (VRP). In general, the PDPs involve designing minimum-cost routes for a set of vehicles to satisfy all the pickup-delivery requests. Pairing and precedence relations of pickup and delivery locations must be respected. Variants of PDPs are found by adding side constraints such as time windows, vehicle capacity, etc. This class of optimization problems has applications in several real-life contexts, such as door-to-door passenger transportation, urban courier services, maritime shipping and freight transportation. PDPs have been widely addressed in the literature. However, modern delivery networks with more and more complex operations and special characteristics make conventional methods limited and/or inefficient. Hence, developing new innovative solution methods to tackle the new challenges of the transportation industry is crucial. In this research project, we tackle real-life PDPs arising from different contexts, such as last mile delivery and healthcare services. First, we study a new rich PDP in the context of last mile delivery known as the multi-pickup and delivery problem with time windows (MPDPTW). This problem finds many real-life applications, some of them are in the context of shared economy such as UBER EAT services, where a client is allowed to order food from different restaurants; the company must then perform all pickups at different places, before delivering all meals to the client location. We designed a new branch-and-cut algorithm for the MPDPTW providing the first dual bounds for the problem and obtaining tight solutions for large instances. In this work, two new formulations for the problem are introduced, a two-index formulation and the asymmetric representatives formulation (ARF). A transformation of the MPDPTW into a PDPTW is also proposed and tested. The mathematical formulations are then compared to define the best one for the problem. The second problem tackled in this research project is a PDP-related application in the context of healthcare logistics. Transportation activities in hospitals are now becoming more complex due to the wide variety of supplies and equipment used such as disposable items which are being used more frequently. This results in the expansion of the volume of transportation in hospitals. These factors justify the need for more efficiency and productivity of transportation systems in hospitals in order to meet the service level expected by patients without increasing costs. One of the most powerful ways of achieving these goals is the automation of logistics processes by using automated guided vehicles. We study the fleet sizing and routing problem with synchronization of automated guided vehicles with dynamic demands in the context of a real-life application with an industrial partner from the healthcare industry in Quebec City, Canada. We describe the problem, introduce a mathematical formulation for it, and propose a powerful matheuristic to solve it. Computational experiments are conducted on large and small instances generated based on real-data provided by our industrial partner. The third problem studied in this project is another application, this time in the context of ready-mixed concrete (RMC) delivery. Many challenging operational problems are faced by RMC suppliers such as scheduling production operations at production plants, creating daily and weekly drivers' schedules, loading operations scheduling, and delivering concrete to construction sites. In a business environment characterized by a fierce competition, innovative solutions are needed to tackle these problems in order to achieve operational efficiency and guarantee a competitive advantage. Although optimizing concrete delivery operations is essential for concrete companies, drivers' and customers' satisfaction should not be neglected. We study the personnel scheduling problem for RMC delivery in the context of a real-life application with a concrete company in Quebec, Canada. The goal is to help RMC suppliers build cost-effective and consistent (similar starting times over the week) drivers' schedules over a large planning horizon, under tight operational and regulatory constraints. The PSP-RMC embeds a PDP which is solved to create routes for drivers. We describe the problem and propose a two-stage metaheuristic algorithm to solve it. Computational experiments are conducted on artificial instances, and on instances generated based on real-data provided by our industrial partner. This thesis is structured as follows. A literature review on the pickup and delivery problems is presented after an introductory chapter. Chapter 2 is devoted to the multi-pickup and delivery problem with time windows, and Chapter 3 presents the fleet sizing and routing problem with synchronization of automated guided vehicles with dynamic demands. Chapter 4 presents the personnel scheduling problem for ready-mixed concrete delivery. The conclusion follows and summarizes the main contributions of this thesis in the last Chapter.

Download or read book Pickup and Delivery Problems with Side Constraints written by Yuan Qu (Ph. D.) and published by . This book was released on 2012 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pickup and delivery problems (PDPs) have been studied extensively in past decades. A wide variety of research exits on both exact algorithms and heuristics for generic variations of the problem as well as real-life applications, which continue to spark new challenges and open up new opportunities for researchers. In this dissertation, we study two variations of pickup and delivery problem that arise in industry and develop new computational methods that are shown to be effective with respect to existing algorithms and scheduling procedures found in practice. The first problem is the pickup and delivery problem with transshipment (PDPT). The work presented here was inspired by a daily route planning problem at a regional air carrier. In structuring the analysis, we describe a unique way to model the transshipment option on a directed graph. With the graph as the foundation, we implemented a branch and price algorithm. Preliminary results showed that it has difficulty in solving large instances. As an alternative, we developed a greedy randomized adaptive search procedure (GRASP) with several novel features. In the construction phase, shipment requests are inserted into routes until all demand is satisfied or no feasible insertion exists. In the improvement phase, an adaptive large neighborhood search algorithm is used to reconstruct portions of the feasible routes. Specialized removal and insertion heuristics were designed for this purpose. We also developed a procedure for generating problem instances in the absence of any in the literature. Testing was done on existing PDP data sets and generated PDPT data set. For the former, the performance and solution quality of the GRASP were comparable to the best known heuristics. For the latter, GRASP found the near optimal solution in most test cases. In the second part of the dissertation, we focus on a new version of the heterogeneous PDP in which the capacity of each vehicle can be modified by reconfiguring its interior to satisfy different types of customer demands. The work was motivated by a daily route planning problem arising at a senior activity center. A fleet of configurable vans is available each day to transport participants to and from the center as well as to secondary facilities for rehabilitative and medical treatment. To find solutions, we developed a two-phase heuristic that makes use of ideas from greedy randomized adaptive search procedures with multiple starts. In phase I, a set of good feasible solutions is constructed using a series of randomized procedures. A representative subset of those solutions is selected as candidates for improvement by solving a max diversity problem. In phase II, an adaptive large neighborhood search (ALNS) heuristic is used to find local optima by reconstructing portions of the feasible routes. Also, a specialized route feasibility check with vehicle type reassignment is introduced to take full advantage of the heterogeneous nature of vehicles. The effectiveness of the proposed methodology is demonstrated by comparing the solutions it provided for the equivalent of several weeks with those that were used in practice and derived manually. The analysis indicates that anywhere from 30% to 40% savings can be achieved with the multi-start ALNS heuristic. An exact method is introduced based on branch and price and cut for settings with more restricted time windows. In the procedure, the master problem at each node in the search tree is solved by column generation to find a lower bound. To improve the bound, subset-row inequalities are applied to the variables of the master problem. Columns are generated by solving the pricing subproblems with a labeling algorithm enhanced by new dominance conditions. Local search on the columns is used to quickly find promising alternatives. Implementation details and ways to improve the performance of the overall procedure are discussed. Testing was done on a set of real instances as well as a set of randomly generated instances with up to 50 customer requests. The results show that optimal solutions are obtained in majority of cases.

Download or read book The Single and Multiple Vehicle Pickup and Delivery Problem written by Gerald R. Armstrong and published by . This book was released on 1981 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: The pickup and delivery problem (PUDP) represents a class of sequencing or routing problems where the key facet of the routing is that a pickup must precede the corresponding, subsequent delivery. Other considerations such as service time windows, quality of service parameters or operational constraints on either the driver or the vehicle are possible. As such, the PUDP is a constrained version of the ubiquitous travelling salesman problem (TSP), which seeks a minimum cost route that from an initial point visits each city or stop once and only once, ending at the initial stop. There are also similarities between the PUDP and the much studied vehicle routing problem (VRP), although the two problems are distinctly different because of the origin preceding destination requirement.

Download or read book Heuristic Algorithms for Solving the Pickup and Delivery Problem written by Alan Hartwell Bills and published by . This book was released on 1976 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigating Heuristic and Meta heuristic Algorithms for Solving Pickup and Delivery Problems written by Manar Ibrahim Hosny and published by . This book was released on 2010 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Pickup and Delivery Problem with Time Windows and Precedences written by Mikkel Sigurd and published by . This book was released on 2000 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: "In the classical Vehicle Routing Problem (VRP) we wish to service some geographically scattered customers with a given number of vehicles at the minimal cost. In the present paper we consider a variant of the VRP where the vehicles should deliver some goods between groups of customers. The customers have an associated time window, a precedence number and a quantity. Each vehicle should visit the customers within their time windows, in nonincreasing order of precedence and such that the capacity of the vehicle is respected. The problem will be denoted the Pickup and Delivery Problem with Time Windows and Precedency constraints (PDPTWP). PDPTWP has applications in the transportation of live animals where veterinary rules demand that the livestocks are visited in a given sequence in order not to spread specific diseases. A tight formulation based on Dantzig-Wolfe decomposition is proposed. The formulation splits the problem into a master problem, which is a kind of set-covering problem, and a subproblem which generates legal routes for a single vehicle. The LP-relaxation of the decomposed problem is solved through delayed column generation, and computational experiments show that the obtained bounds are less than 0.7% from optimum for practical problems. Exact and heuristic algorithms for the subproblem are presented and their complexity is discussed. Moreover several branching strategies for reaching an integer solution are presented. The paper is concluded with a comprehensive computational study involving real-life instances from the transportation of live pigs."

Download or read book A Heuristic Algorithm for the Multi period Vehicle Routing Problem with Simultaneous Pickup and Delivery Service written by Liangyu Xu and published by . This book was released on 2010 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Resources Synchronization in a Full Truck Load Pickup and Delivery Problem written by Luciana Melchiori and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: For many industries, logistic activities encompass an important part of the total costs and sometimes, the success of the company strongly depends on the performance of these activities. Counting on a good transportation plan is a key issue to obtain desirable achievements. In general, these activities involve allocation, routing and scheduling integrated decisions, which turn the problem difficult to be solved. In this work, a mathematical programming model for the simultaneous optimization of these three decision levels for a general full truck-load pickup and delivery problem with time windows and resources synchronization is proposed. In order to improve the model performance, constraints management through reformulations, valid inequalities and symmetric-breaking constrains are studied and implemented. Moreover, with the aim of provide good initial feasible solutions, an heuristic initialization methodology is proposed. The capabilities of the proposed approach are assessed through several examples. In this way, the main contribution of this work is providing an efficient approach for solving the hard and complex daily transportation problem of materials within a supply chain.

Download or read book Heuristics and Exact Approaches for Transportation Problems with Pickup and Delivery written by Francesco Carrabs and published by . This book was released on 2006 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Heuristics for Dynamic Vehicle Routing Problems with Pickups and Deliveries and Time Windows written by Penny Louise Holborn and published by . This book was released on 2013 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work presented in this thesis concerns the problem of dynamic vehicle routing. The motivation for this is the increasing demands on transportation services to deliver fast, efficient and reliable service. Systems are now needed for dispatching transportation requests that arrive dynamically throughout the scheduling horizon. Therefore the focus of this research is the dynamic pickup and delivery problem with time windows, where requests are not completely known in advance but become available during the scheduling horizon. All requests have to be satisfied by a given fleet of vehicles and each request has a pickup and delivery location, along with a time window at which services can take place. To solve the DPDPTW, our algorithm is embedded in a rolling horizon framework, thus allowing the problem to be viewed as a series of static sub-problems. This research begins by considering the static variant of the problem. Both heuristic and metaheuristic methods are applied and an analysis is performed across a range of well-known instances. Results competitive with the state of the art are obtained. For the dynamic problem, investigations are performed to identify how requests arriving dynamically should be incorporated into the solution. Varying degrees of urgency and proportions of dynamic requests have been examined. Further investigations look at improving the solutions over time and identifying appropriate improvement heuristics. Again competitive results are achieved across a range of instances from the literature. This continually increasing area of research covers many real-life problems such as a health courier service. Here, the problem consists of the pickup and delivery of mail, specimens and equipment between hospitals, GP surgeries and health centres. Final research applies our findings to a real-life example of this problem, both for static schedules and a real-time 24/7 service.

Download or read book Network Design with Applications to Transportation and Logistics written by Teodor Gabriel Crainic and published by Springer Nature. This book was released on 2021-07-16 with total page 668 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explores the methodological and application developments of network design in transportation and logistics. It identifies trends, challenges and research perspectives in network design for these areas. Network design is a major class of problems in operations research where network flow, combinatorial and mixed integer optimization meet. The analysis and planning of transportation and logistics systems continues to be one of the most important application areas of operations research. Networks provide the natural way of depicting such systems, so the optimal design and operation of networks is the main methodological area of operations research that is used for the analysis and planning of these systems. This book defines the current state of the art in the general area of network design, and then turns to its applications to transportation and logistics. New research challenges are addressed. Network Design with Applications to Transportation and Logistics is divided into three parts. Part I examines basic design problems including fixed-cost network design and parallel algorithms. After addressing the basics, Part II focuses on more advanced models. Chapters cover topics such as multi-facility network design, flow-constrained network design, and robust network design. Finally Part III is dedicated entirely to the potential application areas for network design. These areas range from rail networks, to city logistics, to energy transport. All of the chapters are written by leading researchers in the field, which should appeal to analysts and planners.

Download or read book Meta Heuristic Algorithms in Supply Chain Logistics and Transportation written by Aidin Delgoshaei and published by Wiley. This book was released on 2021-08-03 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book shows how Meta-heuristic algorithms can be developed by using MATLAB for Supply Chain and Logistics problems. The book begins with an explanation of various problems in the field of supply chain, logistics and transportation. Then, optimization methods that are frequently used for the mentioned problems are explained and some problems are solved using these methods by Lingo and GAMS. The book continues by outlining reasons for using heuristics and metaheuristics for complicated problems in supply chain and logistics. This book helps readers understand each commonly used metaheuristic method, understand its elements quickly, as well as applications of it and how to code using MATLAB. This book will help graduate students as well as researchers understand which metaheuristic method can be used for their applications. This book will also help readers have a clear vision of choosing the appropriate algorithm for their problems by considering different elements like the number of operators, the number of agents, and convergence rate of the algorithm.

Download or read book A Heuristic Algorithm for the Capacitated Vehicle Routing Problem with Synchronized Pick ups and Drop offs written by John Clarke and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Routing Heuristic for the Pickup and Delivery Traveling Salesman Problem written by Fayez Fouad Boctor and published by Montréal : Télé-université. This book was released on 1997 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Recent Heuristics and Exact Methods for Solving the Split Delivery Vehicle Routing Problem written by Anders Brink Agger and published by . This book was released on 2013 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Vehicle Routing Problem written by Paolo Toth and published by . This book was released on 2002 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Smart Delivery Systems written by Jakub Nalepa and published by . This book was released on 2019-11 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: Smart Delivery Systems: Solving Complex Vehicle Routing Problems examines both exact and approximate methods for delivering optimal solutions to rich vehicle routing problems, showing both the advantages and disadvantages of each approach. It shows how to apply machine learning and advanced data analysis techniques to improve routing systems, familiarizing readers with the concepts and technologies used in successfully implemented delivery systems. The book explains both the latest theoretical and practical advances in intelligent delivery and scheduling systems and presents practical applications for designing new algorithms for real-life scenarios. Emphasizes both sequential and parallel algorithms Uniquely combines methods and algorithms, real-life applications, and parallel computing Includes recommendations on how to choose between different methods for solving applications Provides learning aids, end of chapter references, bibliography, worked examples and exercises