Master Production Scheduling System Research Articles

Master Production Scheduling and a comparison of Material Requirements Planning and cover-time planning

For a company's long-term profitability, the most important processes are the way it starts parts of the manufacturing process before the customer order arrives and the way it determines and promises delivery quantities and times for customer orders. In practical computer applications Material Requirement Planning (MRP) and/or Reorder point systems are the base techniques mostly used. This paper presents Cover-Time Planning (CTP), a variant of a reorder point system, which is developed with a forward-looking forecasted demand rate and the decision variable is ‘time’, instead of ‘quantity’ for an ordinary reorder-point system. MRP and CTP are introduced and compared through a numerical example. MRP and CTP must treat a practical ‘make-to-order’; therefore, this paper discusses available-to-promise, planning bills and other help systems for practical applications of Master Production Scheduling. The paper presents how and why, in practice, a Master Production Scheduling system with an available-to-promise function should be used and how this system should be designed. It is also argued that a fully Enterprise Resource Planning (ERP) system cannot only be created by MRP, but also by CTP.

THE DESIGN OF MASTER PRODUCTION SCHEDULING SYSTEM FOR BALL GRID ARRAY PACKAGING PROCESS

ABSTRACT The wafer bumping process in Ball Grid Array (BGA) packaging has three characteristics: long machine setup time, dynamical arrival of orders, and re-entrance of operations. These three properties make a factory with BGA packaging difficult to maximize its capacity utilization while having all orders meeting their due dates. Therefore, we design a master production scheduling (MPS) system for wafer bumping process which aims for having high due date achievement as well as doing customer order promising. The MPS system first estimates the cycle time roughly. Then a mixed integer programming (MIP) model is applied to optimize the setup schedule. With estimated cycle times and setup schedules, the master production scheduling system can plan master production schedules wich are capable to meet the due date requirement and can handle the task of customer order promising. The case studies show that this MPS system generates feasible master production schedules with high due date achievement.

A rule-based master production scheduling system for an electro-mechanical manufacturing company

It is a hard process to modify master production schedule in a firm having various types of products and final assembly groups. Therefore, the system should automatically make the needed and proper modifications when they are input. Besides, it is of great importance to the firm to remove the errors of demand forecasting so as not to reject customer orders. In this study, a rule-based system for an electromechanical manufacturing company, which is able to rearrange the master production schedule, is presented. This system will provide considerableeasinessofusein themaster production scheduling activities.

Earliness/tardiness producution planning by JIT philosophy for job-lot manufacturing systems

In this paper, we study the problem of production planning for the typical job-lot manufacturing system. The production in this kind of manufacturing system has such features as global-market-oriented, one-of-a-kind production, differentiating products with high manufacturing cost, complicated structure and long manufacturing cycle time. Just-in-time production and delivery is the key element to be considered. Here, an earliness/tardiness production planning approach is proposed. It is compatible with the concept of JIT production and extends study of the single machine earliness/tardiness (E/ T) scheduling problem. An E/T production planning model is established which minimizes the earliness and tardiness penalties of all products under total production capacity constraint. The Lagrangian relaxation algorithm is developed to solve the model. To combine MRP-II with JIT philosophy, we have embedded the E/T planning approach into the master producproduction tion scheduling (MPS) or MRP-II, and have designed a hierarchical master production scheduling system. The E/T production planning approach and the designed MPS system are successfully applied to the computer integrated manufacturing system (CIMS) of the Shenyang Blower Plant in China, a typical one-of-a-kind manufacturing plant. Satisfactory results are reported.

The effects of environmental factors on the design of master production scheduling systems

AbstractIn uncertain environments, firms often use a rolling schedule to implement a master production schedule (MPS). The rolling schedule involves replanning the MPS periodically and freezing a portion of the MPS in each planning cycle. Two important decisions which have a significant impact on the cost performance of a rolling schedule are the choice of a replanning interval (R), which determines the replanning frequency of the MPS, and the selection of a frozen interval (F), which represents the number of periods the MPS is frozen in each planning cycle. The determination of the appropriate F and R values has been an important research issue, especially in an uncertain environment.This paper examines the effects of environmental factors such as cost structure, bill of material (BOM) structure, cumulative lead time, magnitude of MPS change costs, and the magnitude of forecast error on the choice of F and R for a single end item in an uncertain environment where a rolling schedule is used. Results of our investigation show that the choice of F affects total system costs per period (TC) but the effects of the choice of R on TC is situational. In addition, the analysis indicates that the magnitude of the MPS change costs, the BOM structure, and the cumulative lead time of the product are important considerations in the design of MPS systems. Results also show that the magnitude of the forecast errors and the cost structure play relatively minor roles in the choice of F and R. We also show that even when MPS change costs are high, greater freeze intervals and more frequent replanning may be cost effective.

Gap Analysis Approach to the Effective Implementation of Master Production Scheduling Systems

Develops and describes a knowledge‐based systems approach which may be used to highlight the disparity between the essential and/or desirable prerequisites for the implementation of effective master production scheduling (MPS) systems and what actually exists in a given manufacturing environment. Identifies seven high level MPS implementation issues: level of understanding of MPS systems; procedures and responsibilities for MPS creation; planning horizons, time‐buckets and time fences; capacity feasibility of the MPS; dealing with backlogs; adherence to the MPS; and what to master schedule. Asks questions to determine the presence or absence of necessary prerequisites. If a high level prerequisite, relating to procedures and data, is not present, further lower level questions are asked to assess the reasons for its lack, and how it may be provided. This gap analysis approach makes it possible to identify in advance the major problems which must be addressed to ensure the effective implementation of master production scheduling systems.

A Comparative Analysis of Master Production Scheduling Techniques for Assemble‐To‐Order Products

ABSTRACTThis paper studies the master production scheduling (MPS) activity of manufacturing firms that produce assemble‐to‐order (ATO) products. It describes four techniques for master scheduling ATO products: end‐product bills, modular bills, super bills, and percentage bills. These procedures are compared in terms of the percentage of customer orders delivered late, the mean tardiness of customer order deliveries, and the total cost of inventory using simulation analysis. The results indicate that the performance of an MPS technique is affected by the level of uncertainty of the end products' demands and the degree of component commonality in the product structure. In particular, modular bills produce the highest customer service level and super bills produce the lowest total inventory cost under most operating conditions. The conclusions also suggest that the choice of a particular MPS technique is often a compromise between the benefits of improved MPS performance and the costs of implementing and executing the MPS system.