A two-dimensional cutting stock problem (2DCSP) needs to cut a set of given rectangular items from standard-sized rectangular materials with the objective of minimizing the number of materials used. This problem frequently arises in different manufacturing industries such as glass, wood, paper, plastic, etc. However, the current literatures lack a deterministic method for solving the 2DCSP. However, this study proposes a global method to solve the 2DCSP. It aims to reduce the number of binary variables for the proposed model to speed up the solving time and obtain the optimal solution. Our experiments demonstrate that the proposed method is superior to current reference methods for solving the 2DCSP.

Seminar paper from the year 2020 in the subject Business economics - Operations Research, grade: 1,3, University of Kaiserslautern, language: English, abstract: The Cutting Stock Problem (CSP) appears when a material has to be cut into smaller pieces and occurs in many branches of industry. On the one hand, the CSP belongs to the earliest studied problems through methods of Operational Research and on the other to the most intensively studied problems in combinatorial optimization. In the one-dimensional Cutting Stock Problem (1DCSP), there are typically identical pieces of a single standard length, called rolls, that need to be cut into smaller pieces lengthwise. Examples, where the cutting process is performed in one single dimension, can be found in the steel industry and the paper industry . The two-dimensional CSP (2DCSP) is classified into cutting of regular and irregular shapes and is often found in clothing and shoe-leather industries. A real-world application of a three-dimensional CSP (3DCSP) lies in the production of mattresses, where rubber blocks are cut into different types of orthogonal rectangular prisms. Methods of finding an optimal solution exist for the 1DCSP. Often in large problem instances, the required time for finding an optimal solution proliferates, and heuristics may turn out to be the more sensible option in this case. Nowadays, there are countless different ways to find acceptable solutions in a fast manner of time, among others, the column generation approach, which is the central component of the present work. This work is organized as follows. In Chapter 2, a brief overview of different formulations for the CSP is given. Furthermore, some known extensions of the classic CSP are presented, e.g., raw material, that consists of various sizes at the same time. CSP has many relatives, the closest is the Bin Packing Problem (BPP), where items are packed into bins as efficiently as possible. The third chapter shows the column generation technique for solving the CSP and provides the connection between a solution for the relaxed problem and an integer solution. In Chapter 4, different test instances of the CSP are compared using a column generation implementation solved in three different MIP solvers. The conclusion is provided in Chapter 5.

Column Generation is an insightful overview of the state of the art in integer programming column generation and its many applications. The volume begins with "A Primer in Column Generation" which outlines the theory and ideas necessary to solve large-scale practical problems, illustrated with a variety of examples. Other chapters follow this introduction on "Shortest Path Problems with Resource Constraints," "Vehicle Routing Problem with Time Window," "Branch-and-Price Heuristics," "Cutting Stock Problems," each dealing with methodological aspects of the field. Three chapters deal with transportation applications: "Large-scale Models in the Airline Industry," "Robust Inventory Ship Routing by Column Generation," and "Ship Scheduling with Recurring Visits and Visit Separation Requirements." Production is the focus of another three chapters: "Combining Column Generation and Lagrangian Relaxation," "Dantzig-Wolfe Decomposition for Job Shop Scheduling," and "Applying Column Generation to Machine Scheduling." The final chapter by François Vanderbeck, "Implementing Mixed Integer Column Generation," reviews how to set-up the Dantzig-Wolfe reformulation, adapt standard MIP techniques to the column generation context (branching, preprocessing, primal heuristics), and deal with specific column generation issues (initialization, stabilization, column management strategies).

1 Introduction.- 1.1. Purpose of the Investigation.- 1.2. Methodology Used.- 1.3. Structure of the Book.- 2 Cutting and Packing Problems as Geometric-Combinatoric Problems.- 2.1. Basic Logical Structure.- 2.2. Phenomena of Cutting and Packing.- 2.2.1. Cutting and Packing in Spatial Dimensions.- 2.2.2. Cutting and Packing in Abstract Dimensions.- 2.2.3. Related Problems.- 2.3. Delimitation in Investigation.- 3 The Treatment of Cutting and Packing Problems in the Literature.- 3.1. Models as Idealized Images of Actual Phenomena.- 3.2. Sources on Cutting and Packing Problems.- 3.2.1. Differentiation According to Thematic Criteria.- 3.2.2. Differentiation According to Bibliographical Criteria.- 3.3. Delimitation of Investigated Literature.- 4 Systematic Catalogue of Properties for the Characterization of Cutting and Packing Problems.- 4.1. Basis for Characteristic Properties.- 4.2. Design of the Catalogue.- 4.3. Characteristics Based on the Logical Structure.- 4.3.1. Dimensionality.- 4.3.2. Type of Assignment.- 4.3.3. Characteristics of Large Objects and Small Items.- 4.3.4. Pattern Restrictions.- 4.3.5. Objectives.- 4.3.6. Status of Information and Variability of Data.- 4.3.7. Solution Methods.- 4.4. Reality-Based Characteristics.- 4.4.1. Kind of Objects and Items, and Branch of Industry.- 4.4.2. Planning Context.- 4.4.3. Software.- 4.5. Overview.- 5 Types of Cutting and Packing Problems in the Literature.- 5.1. Principles of Type Definition.- 5.2. Hierarchical Catalogue of Types.- 5.2.1. General Types.- 5.2.2. Special Types.- 5.2.3. Summarized Description of the Hierarchy of Types.- 5.3. Properties of the Derived Problem Types.- 6 Bin Packing Types (BP).- 6.1. One-dimensional Bin Packing Type (BP1).- 6.2. Two-dimensional Bin Packing Types (BP2).- 6.2.1. BP2-Type with a Heterogeneous Assortment of Large Objects.- 6.2.2. BP2-Type with a Homogeneous Assortment of Large Objects.- 6.3. Actual Bin Packing Problems.- 7 Cutting Stock Types (CS).- 7.1. One-dimensional Cutting Stock Types (CS1).- 7.1.1. CS1-Type with Continuous Quantity Measurement of Large Objects.- 7.1.2. CS1-Types with Discrete Quantity Measurement of Large Objects.- 7.1.2.1. Discrete CSl-Type with a Homogeneous Assortment of Large Objects.- 7.1.2.2. Discrete CSl-Type with a Heterogeneous Assortment of Large Objects.- 7.2. Two-dimensional Cutting Stock Types (CS2).- 7.2.1. CS2-Type with Non-rectangular Small Items.- 7.2.2. CS2-Types with Rectangular Small Items.- 7.2.2.1. Rectangular CS2-Types with Only One Large Object per Figure.- 7.2.2.2. Rectangular CS2-Types with Guillotine Patterns.- 7.2.2.3. Rectangular CS2-Type with Nested Patterns.- 7.3. Three-dimensional Cutting Stock Type (CS3).- 7.4. Actual Cutting Stock Problems.- 8 Knapsack Types (KS).- 8.1. One-dimensional Knapsack Type (KS1).- 8.2. Two-dimensional Knapsack Type (KS2).- 8.3. Three-dimensional Knapsack Type (KS3).- 8.4. Actual Knapsack Problems.- 9 Pallet Loading Types (PL).- 9.1. Two-dimensional Pallet Loading Type (PL2).- 9.2. Three-dimensional Pallet Loading Type (PL3).- 9.3. Actual Pallet Loading Problems.- 10 Conclusions.- I. A Bibliography of Further C&P-Problems.- A. Published Surveys.- B. Literary References not Closely Analysed.- C. Most Recent Sources.- II. Brief Description of the Characteristics.- III. LARS Data Base System.- List of Abbreviations for the Journals.- I. General Literature.- II. C&P-Literature.

This book gathers a selection of refereed papers presented at the “International Conference on Operations Research OR2015,” which was held at the University of Vienna, Austria, September 1-4, 2015. Over 900 scientists and students from 50 countries attended this conference and presented more than 600 papers in parallel topic streams as well as special award sessions. Though the guiding theme of the conference was “Optimal Decision and Big Data,” this volume also includes papers addressing practically all aspects of modern Operations Research.

​This book presents practical algorithms for solving a wide variety of cutting and packing problems from the perspective of combinatorial optimization. Problems of cutting and packing objects in one-, two-, or three-dimensional space have been extensively studied for many years because of numerous real applications—for instance, in the clothing, logistics, manufacturing, and material industries. Cutting and packing problems can be classified in three ways according to their dimensions: The one-dimensional problem is the most basic category of problems including knapsack problems, bin packing problems, and cutting stock problems, among others. The two-dimensional problem is a category of geometric problems including rectangle packing problems, circle packing problems, and polygon packing problems, among others. The three-dimensional problem is the most difficult category of problems and has applications in container loading, cargo and warehouse management and so forth. Most of these variants are NP-hard, since they contain as a special case the knapsack problem or the bin packing problem, which are already known to be NP-hard. Therefore, heuristics and metaheuristics are very important to design practical algorithms for these problems. We survey practical algorithms for solving a wide variety of cutting and packing problems in this book. Another feature of cutting and packing problems is the requirement to develop powerful geometric tools to handle the wide variety and complexity of shapes that need to be packed. We also survey geometric properties and tools for cutting and packing problems in the book.

An accessible treatment of the modeling and solution of integer programming problems, featuring modern applications and software In order to fully comprehend the algorithms associated with integer programming, it is important to understand not only how algorithms work, but also why they work. Applied Integer Programming features a unique emphasis on this point, focusing on problem modeling and solution using commercial software. Taking an application-oriented approach, this book addresses the art and science of mathematical modeling related to the mixed integer programming (MIP) framework and discusses the algorithms and associated practices that enable those models to be solved most efficiently. The book begins with coverage of successful applications, systematic modeling procedures, typical model types, transformation of non-MIP models, combinatorial optimization problem models, and automatic preprocessing to obtain a better formulation. Subsequent chapters present algebraic and geometric basic concepts of linear programming theory and network flows needed for understanding integer programming. Finally, the book concludes with classical and modern solution approaches as well as the key components for building an integrated software system capable of solving large-scale integer programming and combinatorial optimization problems. Throughout the book, the authors demonstrate essential concepts through numerous examples and figures. Each new concept or algorithm is accompanied by a numerical example, and, where applicable, graphics are used to draw together diverse problems or approaches into a unified whole. In addition, features of solution approaches found in today's commercial software are identified throughout the book. Thoroughly classroom-tested, Applied Integer Programming is an excellent book for integer programming courses at the upper-undergraduate and graduate levels. It also serves as a well-organized reference for professionals, software developers, and analysts who work in the fields of applied mathematics, computer science, operations research, management science, and engineering and use integer-programming techniques to model and solve real-world optimization problems.