Application of clustering algorithm for storage location assignment problem in synchronized zone order pciking warehouses

VIET NAM NATIONAL UNIVERSITY HO CHI MINH CITY HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY HUYNH HUU DUC APPLICATION OF CLUSTERING ALGORITHM FOR STORAGE LOCATION ASSIGNMENT PROBLEM IN SYNCHRONIZED ZONE O[.]

VIET NAM NATIONAL UNIVERSITY HO CHI MINH CITY HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY HUYNH HUU DUC APPLICATION OF CLUSTERING ALGORITHM FOR STORAGE LOCATION ASSIGNMENT PROBLEM IN SYNCHRONIZED ZONE ORDER PICKING WAREHOUSES Major: Industrial Engineering Major ID: 8520117 MASTER THESIS HO CHI MINH CITY, January 2023 THIS RESEARCH IS COMPLETED AT: HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY – VNU HCM Instructor: PhD Nguyen Duc Duy ………………………………………………… Examiner 1: PhD Do Thanh Luu…………………………………………………… Examiner 2: PhD Le Song Thanh Quynh…………………………………………… Master’s Thesis is defended at HCMC University of Technology, VNU-HCM on January 08, 2023 The Board of The Master’s Thesis Defense Council includes: Chairman: Assoc Prof PhD Do Ngoc Hien…………………………………… Secretary: PhD Le Duc Dao…………………………………………………… Counter-Argument Member: PhD Do Thanh Luu…………………………… Counter-Argument Member: PhD Le Song Thanh Quynh…………………… Council Member: PhD Nguyen Van Thanh…………………………………… Verification of the Chairman of the Master’s Thesis Defense Council and the Dean of the Faculty of Mechanical Engineering after the thesis is corrected (if any) CHAIRMAN OF THE COUNCIL DEAN OF FACULTY OF MECHANICAL (Full name and signature) ENGINEERING (Full name and signature) i VIETNAM NATIONAL UNIVERSITY HCMC SOCIALIST REPUBLIC OF VIETNAM VNUHCM UNIVERSITY OF TECHNOLOGY Independence – Liberty – Happiness MASTER’S THESIS ASSIGNMENTS Full name: HUYNH HUU DUC Learner ID: 2070127 Date of birth: August 08, 1997 Place of birth: Long An Major: Industrial Engineering Major ID: 8520117 I – TITLE: APPLICATION OF CLUSTERING ALGORITHM FOR STORAGE LOCATION ASSIGNMENT PROBLEM IN SYNCHRONIZED ZONE ORDER PICKING WAREHOUSES/ ỨNG DỤNG GIẢI THUẬT PHÂN CỤM VÀO BÀI TỐN XÁC ĐỊNH VỊ TRÍ LƯU TRỮ TRONG KHO LẤY HÀNG ĐỒNG THỜI ASSIGNMENTS AND CONTENT: Assignments: • Understanding the structure of k-means clustering algorithms • Understanding the problem of storage location assignment in synchronized order picking warehouses • Applying the k-means clustering algorithm in a suitable way to solve the problem of storage location assignment in synchronized order picking warehouses • Demonstrating the effectiveness of the proposed algorithm by using different data sets in the scope and goals of the thesis Content: • Chapter gives some introduction and determines the goal and scope of the study ii • Chapter reports the literature review and shows the methodology of the study • Chapter presents the problem statement and the modified design of the clustering algorithm • Chapter shows the experimental validation and analysis results to prove the ability and extent of the proposed algorithm to the problem • Chapter gives conclusion statements and some suggestions for future studies II – ASSIGNMENT DELIVERING DATE (based on the Decision on Assignments Delivering): September 05, 2022 III – ASSIGNMENT COMPLETING DATE (based on the Decision on Assignments Delivering): December 18, 2022 IV – INSTRUCTOR: PhD Nguyen Duc Duy Ho Chi Minh City, ………………………… INSTRUCTOR HEAD OF DEPARTMENT (Full name and signature) (Full name and signature) DEAN OF FACULTY OF MECHANICAL ENGINEERING (Full name and signature) iii ACKNOWLEDGEMENTS This thesis is completed with the valuable support of many people First of all, I would like to express my special and sincere gratitude to my research advisor PhD Nguyen Duc Duy for thoughtfully instructing and consulting me during two hard semesters of conducting this thesis Secondly, I want to express many thanks to Assoc.Prof PhD Do Ngoc Hien, Head of Department of Industrial Systems Engineering, Ho Chi Minh City Univeristy of Technology for kindly giving me a good environment to work and study I am also grateful to all staff of Department of of Industrial Systems Engineering and members of Faculty of Mechanical Engineering for their kindness and sympathy when I carry out this thesis Last but not least, it is my pleasure and lucky to be my parents’ son and to be a member of my close friends’ circle as well as my extended family Thanks so much to them for accompanying me not only in my academic path but also in my memorable life HUYNH HUU DUC iv ABSTRACT The development of E-commerce leads to the appearance of higher numbers of orders but with smaller amounts of item quantities per order In this situation, the important role of warehouses as buffering places is becoming more obvious One of the common and vital performance metrics of warehouse operations is the efficiency of the order-picking phase To improve this metric, several solutions are studied and applied, including the policy of synchronized zone order-picking systems In this thesis, the author tries to prove that in synchronized zone order-picking warehouses, a proper mechanism of storage location assignment can contribute to the improvement rate of order-picking efficiency In more detail, the more the picking demand of two items is similar, the less the likelihood that these items should be located in the same zone should be so that the idle time between pickers when they simultaneously fulfill the order can be cut down, leading to improvement in the completion time of an order Therefore, the author tries to develop a suitable k-means clustering algorithm to release lists of items that should be located in different zones as suggestions for warehouse staff to plan for the storage phase, aiming at improving order-picking efficiency v TÓM TẮT LUẬN VĂN Sự phát triển thương mại điện tử dẫn đến xuất số lượng đơn đặt hàng cao với lượng đặt hàng mặt hàng đơn hàng nhỏ Trong bối cảnh vậy, vai trò đệm quan trọng nhà kho ngày trở nên rõ ràng Một thước đo hiệu suất phổ biến quan trọng hoạt động nhà kho hiệu giai đoạn lấy hàng Để cải thiện số này, số giải pháp nghiên cứu áp dụng, có sách hệ thống lấy hàng đồng thời Trong luận án này, tác giả cố gắng chứng minh kho lấy hàng đồng thời, chế xác định vị trí lưu trữ phù hợp góp phần nâng cao hiệu lấy hàng Cụ thể hơn, nhu cầu lấy hàng hai mặt hàng giống khả mặt hàng nằm khu vực nên nhỏ đi, để thời gian nhàn rỗi người lấy hàng họ thực lấy hàng đồng thời cho đơn hàng cắt giảm, dẫn đến cải tiến thời gian hoàn thành đơn hàng Do đó, tác giả cố gắng phát triển thuật toán phân cụm k-mean phù hợp để đưa danh sách mặt hàng nên đặt khu vực khác nhau, từ cung cấp gợi ý cho nhân viên kho lập kế hoạch cho giai đoạn lưu trữ nhằm nâng cao hiệu lấy hàng vi DECLARATION I hereby declare that this is my own research All the data and the results used in this research are honest and have not been published in other studies I will be totally responsible for my research if it is incorrect as mentioned above The research’s author HUYNH HUU DUC vii CONTENTS MASTER’S THESIS ASSIGNMENTS i ACKNOWLEDGEMENTS iii ABSTRACT iv TÓM TẮT LUẬN VĂN v DECLARATION vi CONTENTS vii List of Figures x List of Tables xi List of Acronyms xii Chapter INTRODUCTION 1.1 Motivation 1.2 Problem statement 1.3 Goal and scope 1.4 Thesis layout Chapter LITERATURE REVIEW AND METHODOLOGY 2.1 Literature review and contributions 2.1.1 Storage location assignment 2.1.2 Synchronized order picking warehouses 2.1.3 Clustering algorithms 2.1.4 Hierarchical and partitional clustering 2.1.5 k-means clustering algorithms 10 2.2 Methodology 11 viii Chapter PROBLEM AND ALGORITHM 14 3.1 Definitions 14 3.2 Solution orientation and concept of flow 14 3.3 Feature selection and distance measure 15 3.4 Clustering evaluation function 17 3.5 Initial cluster centers selection method 18 3.5.1 Dimension reduction component 21 3.5.2 Initialization component 22 3.6 Determination of the number of clusters 26 3.7 Convergence condition 30 3.8 Flow of the algorithm 31 Chapter EXPERIMENTAL RESULTS AND ANALYSIS 35 4.1 Operational context and notations 35 4.2 Input data 35 4.3 Implementation and results 36 4.4 Managerial insights 37 4.5 Discussions on computational complexity 38 Chapter CONCLUSION AND FUTURE DIRECTIONS 40 5.1 Conclusion 40 5.2 Future directions 41 List of Publications 42 References 43 Appendix A INPUT DATA VERSIONS 49