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Chapter 1 - Introduction

The Shop Floor is an integral part of any manufacturing system. It is here that the needs of the customer and the efforts of a manufacturing firm are inter-linked by combining raw materials and labor to make the desired finished product. Consequently, it is important that there should exist an effective means for controlling the activities of the shop floor in order to achieve the greatest efficiency and predictability of the manufacturing process.

 

Different manufacturing systems exist worldwide. In the USA Manufacturing Resource Planning (MRP II) is in use by close to 80% of the manufacturing industry [rough estimate by Scott Ball - LFM]. Initially introduced in the 1960s, MRP II has undergone several revisions fuelled by increased computing capabilities and an effort to integrate the activities of the different sections of the manufacturing firm into one unit. The latest version of MRP is the Advanced Planning System (APS).

 

This study tries to establish the suitability of MRP II as a tool for Shop Floor control. In  general, MRP II is an excellent planning tool especially with regards to optimizing the use of the various manufacturing resources. However at the shop floor level, it experiences certain limitations that constrain its ability to act as an effective tool for control.  The study also attempts to identify what these limitations are and to highlight different solutions that have been proposed or implemented by various companies and researchers to bring MRP II as close as possible to the ideal control system.

 

The scope of the paper is limited only to discussing how MRP II relates to shop floor control in the context of manufacturing. Some technical details of relevance are defined in the paper. In addition, definitions and explanations of the different MRP II concepts that are discussed are given. The paper is divided into two parts. The first  part constituting chapters 2, 3 and 4 provides a review of the literature available on the topics of MRP II and Shop Floor Control.  Chapter 2 begins by giving a description of MRP II. In addition to explaining what it is and how it works, it mentions how the shop floor control module is related to the entire MRP II framework. It also points out problems that are typically associated with MRP II and then proceed to highlight the types of solutions that industry has implemented in the form of MRP II hybrid systems. Chapter 3 discusses what shop floor control (SFC) is and what it entails. It then discusses what the characteristics of the ideal shop floor control design would be. It augments this with a discussion on the difference between push and pull systems with respect to shop floor control. Chapter 4 relates the contents of the previous two chapters by discussing how MRP II establishes shop floor control. It highlights the difficulties faced in doing this by identifying the limitations and constraints of the system using the Manufacturing System Design Decomposition developed by Professor Cochran. It then discusses from a technical viewpoint the various MRP hybrid systems that have arisen to solve these shortcomings as introduced in chapter 2.  The second part of the paper is chapter 5 which provides a case study of a manufacturing firm that uses MRP II in its production process. Through the case study, the paper tries to connect the various characteristics highlighted in the literature review with a real life example. Chapter six gives the conclusions of the study.