Production and Inventory Management

Transcription

1 Production and Inventory Management ARNOLDO C. HAX Massachusetts Institute of Technology DAN CANDEA Polytechnic Institute of Cluj-Napoca TECHNISCHE HOCHSCHULE DARMSTADT FoaiberGirii 1 Gesam th ibl iot h k B e t ii e f i s vv i r t s c h ci l; s I e h f e Abstcil-i 'r. \ Sachgebiete: PRENTICE-HALL, INC., Englewood Cliffs, New Jersey 07632

2 Contents PREFACE ix CHAPTER 1 Introduction 1.1 The Nature of the Production-Inventory Management Systems Anthony's Framework: Strategic, Tactical, and Operational Decisions Strategic Planning: Facilities Design Management Control (Tactical Planning): Aggregate Capacity Planning Operational Control: Detailed Production Scheduling 1.3 Implications of Anthony's Framework: A Hierarchical Integrative Approach The Product Structure Framework Implications of the Product Structure Framework: A Classification of Production-Inventory Systems Types of Production- Inventory Systems Aggregation of Items 1.6 The Diagnostic Process 11 Bibliography 11

3 iv Contents CHAPTER 2 Facilities Design Introduction A Simple Model Formulation 2.2 Issues and Assumptions in Modeling the Facilities Design Problem Nature of the Set of Possible Facility Locations Optimization Criteria and Cost Structure Nature of the Problem Number of Facilities to Be Located Number of Distribution Stages Capacity Restrictions Number of Products Being Distributed 2.3 General Discrete Location-Allocation Problems Features and Formulations Computational Methods 2.4 Other Discrete Space Formulations Location Problems Location-Allocation Problems Minimax Location and Location- Allocation Problems 2.5 Continuous Space Formulations Single-Facility Location Models Multifacility Location and Location- Allocation Models Bibliography 63 CHAPTER 3 Aggregate Production Planning Introduction Ways to Absorb Demand Fluctuations Costs Relevant to Aggregate Production Planning The Role of Models in Aggregate Production Planning 3.2 Linear Cost Models Classical Linear Programming Models Goal Programming Models Advantages and Disadvantages of Linear Cost Models 3.3 Quadratic Cost Models (Linear Decision Rules) Cost Components Model Formulation The Linear Decision Rules

4 Contents Extensions to the HMMS Model Advantages and Disadvantages of Quadratic Cost Models 3.4 Lot Size Models (Fixed Cost Models) [incapacitated Lot Size Models Capacitated Lot Size Models Advantages and Disadvantages of Lot Size Models 3.5 General Cost Models Nonlinear Analytical Models Heuristic Decision Rules Search Decision Rules Simulation Decision Rules Advantages and Disadvantages of General Cost Models Bibliography 117 CHAPTER 4 Inventory Management Introduction Inventories and Their Functions Classification of Inventory Systems Objectives and Structure of Inventory Management System 4.2 Economic Order Quantity Decision Rules Costs in an Inventory System Single Item Economic Order Quantity Decision Rules Multiple Items Economic Order Quantity Decision Rules 4.3 Forecasting Exponential Smoothing Methods for Fast- Moving Items Forecasting over Lead Times Forecast Errors Forecasting Slow-Moving Items Tracking Signals to Monitor the Forecasts 4.4 Safety Stock Decision Rules The ABC Inventory Classification Safety Stocks for Fast-Moving Items Safety Stocks for Slow-Moving Items 4.5 The System Integrative Module Made-to-Order Versus Stock Items Continuous Versus Periodic Review Systems Continuous Review

5 vi Contents Systems Periodic Review Systems Other Issues in Inventory Control Systems 4.6 The System-Management Interaction and Evaluation Module Exchange Curves How Much to Order? Updating Frequency of System Parameters Actions to Be Taken When the Tracking Signal Is Triggered Management Adjustments to Statistical Forecasts Production and Inventory Control System Outputs Bibliography 249 CHAPTER 5 Operations Scheduling Introduction Job Shop Scheduling The Job Shop Process Issues and Assumptions The Single-Machine Shop The Parallel Machine Shop The Flow Shop The General Job Shop Closing Notes 5.3 Project Management Constructing the Network Project Activity Scheduling The PERT Probabilistic Calculations Resource Analysis and Allocation Closing Notes 5.4 Line Balancing Problem Definition Solving the Line Balancing Problem Closing Notes Bibliography 380 CHAPTER 6 Hierarchical Production Planning Systems Introduction Hierarchical Production Planning: A Single-Stage System The Regular Knapsack Method The Hierarchical Structure of the Single-Stage System Aggregate Production Planning for Product Types

6 Contents The Advantages of Aggregate Planning The Family Disaggregation Model The Item Disaggregation Model Issues of Infeasibility and Demand Forecasts Measuring Performance of the Single-stage Hierarchical Planning System Comparing Disaggregation Procedures Modifications Introduced in Regular Knapsack Method Computational Results 6.3 Hierarchical Production Planning: A Two-Stage System Hierarchical Structure for the Two-Stage Production System Aggregate Production Planning for Product Types and Part Types Two-Stage Hierarchical Production Planning System The Disaggregation Procedure 6.4 Material Requirements Planning Comparing Hierarchical Production Planning with Material Requirements Planning The MRP Model Tested Product and Part Structure Computational Results Conclusions Appendix 6.1 Proof of Theorem Appendix 6.2 Proof of Theorem Appendix 6.3 The Data Base for Comparing HPP and MRP Methodologies 460 Bibliography 462 CHAPTER 7 Diagnostic Analysis of a Production and Distribution System Introduction The Scope of the Study Physical Characterization of the Existing Logistics System Production and Distribution Planning and Scheduling System Basic Characteristics of the Existing System Critique of the Existing

7 viii Contents System: Myopic Planning Horizon and External Corrections to the Model Critique of the Existing System: Excessive Level of Detail for Planning Decisions and Inadequate Support for Scheduling Decisions An Alternative Production and Distribution Planning and Scheduling System 7.5 Forecasting Inventory Management Basic Characteristics Components of Inventory at Sales Branches Potential Improvements in Sales Branch Inventory 7.7 Consolidation of Sales Branches Total Cost in Terms of Number of Sales Branches Only Consolidation of Subset of Sales Branches 7.8 Conclusions of the Study Diagnostic Study of Ongoing Logistics System Managerial Recommendations Bibliography 493 Index 495