İmalat kaynakları planlaması

Abstract

ÖZET Günümüzde oldukça hızlanmış olan endüstriyel rekabet; işletmelerin verimliliği artt:ırıcı. çeşitli tedbirler almaya zorlamaktadır. Bu tedbirlerden biri de, üretimin her aşamasında bilgisayarın yoğun bir şekilde kullanımıdır. İşletmelerdeki ana fonksiyonlara karşılık gelen modülleri içererek, üretimin, bilgisayarda planlanmasını, izlenmesini ve kontrolünü hedefleyen MRP II (İmalat Kaynakları Planlaması) yazılımları, bilgisayarın gerçekten etkili bir araç olmasına olanak sağlamaktadır. Ben bu çalışmada, İmalat Kaynakları Planlamasını ele alarak, tanımı, uygulamaya konuluş aşamaları ve bu konuda bir paket programın taşıması gereken özellikleri ve bir MRP Iİ paket programı tanıtımını yaptım. Hazırladığım yüksek lisans tezi yedi bölümden oluşmaktadır. Giriş bölümünde, Bilgisayar Destekli Üretimin tarihsel gelişi mi üzerinde durulmuştur. İkinci bölümde, üretimin ne olduğu üzerinde durulmuş, üretim sistemlerinin tanıtılmasına çalışılmıştır. Üçüncü bölümde, malzeme yönetimi ve üretimdeki rolü üzerinde durulmuştur. Dördüncü bölümde, günümüzün vazgeçilmez araçları olan bilgi sayarlar, donanımları ve işletim sistemleri anlatılmıştır. Beşinci bölümde, çalışmanın temelini oluşturan MRP II sistemi, sistemi oluşturan modüllerin tanıtımı yapılmış, ana modüller olan Ana üretim Planlaması, Kapasite İhtiyaç Planlaması, Dağıtım ihtiyaçları Planlaması, Malzeme İhtiyaç Planlaması ve üretim Kontrolü detaylı olarak açıklanmıştır. Altıncı bölümde, MRP II sisteminin şirketlerde uygulamaya konulmuş aşamalarında atılması gereken adımlar belirtilmiştir. Son bölümde ise MRP II sisteminin uygulamaya konulabilmesinde önemli faktörlerden biri olan mevcut paket programlardan birinin tanıtılmasına çalışılmıştır. - vııı

/ SUMMARY MANUFACTURING RESOURCES PLANNING Increased international competition in the manufacturing in dustries has made the continuous pursuit of greater productivity, lower costs and better customer service a matter of urgency and even survival. The use of modern, computer-based systems of pro duction and inventory control has proved to be an important part of this ongoing race with the competition. For manufacturing companies, the danger lies in lower cost- higher quality producers taking an increasing share of both do mestic and foreign markets. The opportunity lies in new technology that can enable a company to improve both productivity and quality and obtain a competitive edge. The new technology can be divided into two categories : 1. The automation of production activities using computer-aided design and manufacturing, robotics or flexible manufacturing systems, 2. Computer-based production and inventory control. Ultimately, these will be joined in computer-integrated manu facturing. Computer-based production and inventory control embodies po werful new tools for more effective manufacturing management deve loped over the last two decades. Conrjuber based production and in-, ventory control does not simply automate manual systems but, rather, makes possible the use of new and better planning and control concepts and techniques. The most widely used and sucessful computer-based production and inventory control system can be called as Manufacturing Resource Planning (MRP II). This system consists of a number of interconnected Modules or subsystems which are used to manage all facets of pro duction and inventory control and has now been extended to tie in accounting, purchasing, marketing and distribution. Those modules of MRP II are used for different business func tions of a company. Information flow between modules increases the communication between departments and enables them to work better with each other. IX -This work consists of seven parts and the contents of those parts will be given below. In introduction, I tried to give infor mation about historical development of computer integrated manu facturing systems from the first production activities to today's competitive manufacturing environment. In the second chapter, a detailed explanation is given about production and production systems. Third chapter is about the material management, the nature and scope of material systems. The definition of material management, explana tion of inventory management, purchasing, warehousing, transportation, de termining of stock policies are some of the topics of this chapter. In the fourth chapter, I tried to write about the computers those become widely effective on our today' s competitive manufactu ring environment. The definitions of data, information and management informa tion systems, the hardware and the software of the computer sys tems, the files used in computer-based production systems and their contents are given here. After telling about the basic definitions those will be help ful in understanding MRP II systems, the detailed definition of MRP II systems is given in the fifth chapter. Also, the structure and the subsystems of the system is explained in details. Generali, understanding what MRP II is, does not mean that the firm will implement it successfully because of this a direction should be laid out, activities should be identified clearly and a spesific destination should be led. Manufacturing Resource Planning has proven to be an effective management weapon. It has enabled a great many companies to mana ge, their business more professionally with the excellent planning and scheduling information. It provides, the successful MRP II users have made dramatic increases in customer services, significant gains in productivity, much higher inventory turns and large reduc tions in purchase costs. The two key terms that occur through out the sixth chapter are class A MRP II and the Proven Path. Cİass A MRP II represents the destination and the proven path describes how to get there. MRP II is not only a computer-based system, software of and by itself cannot make a company a successful MRP II user but at the same time the lack of a reasonably complete set of software can keep a company from succeeding. As mentioned above MRP II software packages have much importance in implementing this system. In the eighth and the last chapter I tried to tell about the structure and the functions of a MRP II software package. - x -The main objective of this study is to define MRP II system known as the most widely used and successful computer-based pro duction and inventory control and the steps should be taken while implementing it. MRP II has began life in I960' s as Material Requirements Planning. Its inventors were looking for a better method for orde ring material and parts, and they found it in this technique. To day, there is a wide Vciriety of tools and techniques, that have been designed to help companies and their people produce their products better. These include Robotics, Just-In-Time, Quality Circles, CAD/ CAM, Group Technology, Statistical Process Control and more. But none of them will ever yield their full potential unless they're coupled to an effective planning and scheduling system. MRP II can provide the foundation upon which additional pro ductivity and quality enhancements can be built, an environment where these other tools and techniques can reach their full poten tial. Scheduling, knowing routinely what is needed and when via the formal system is fundemental to productivity. MRP II is the ve hicle to get valid plans and schedules not only of materials and parts and production it also means not only of materials and parts and production it also means valid. Schedules of shipments to cus tomers of manpower and machine requirements of required engineering resources, of cash flow and profit. MRP/MRP II is the foundation, the bedrock for true productivity. There are many different MRP II software packages available to industry today. A company can now plan material, capacity, finan ce, marketting, strategy, distribution, manufacturing resources, shop floor control etc. all with the same system. The areas within this system that are most applicable to interfacing with the repe- tetive manufacturing environment are : - Master Production Scheduling (MPS) - Resource Requirements Planning (RRP) - Materials Requirements Planning (MRP) - Capacity Requirements Planning (CRP) - Shop Floor Control (SFC) Each module is covered in subsequent sections.. After learning about MRP II system and its modules, it is time to implement it. Many companies have achieved remarkable results from modern MRP II systems but some of them have fulled. The lack XIof success stems from the approach taken in implementation. Specif icially, the most common serious pitfalls are as follows : i. Lack of management commitment, ii- Insufficient education, iii. Inaccurate data. Implementing MRP II is a major undertaking requiring a substantial commitment of funds and personnel. In addition MRP II requires a change in the way management operates the business. Therefore, without a strong commitment from management there is little hope for success. MRP II will not be a success by itself, Rather, it is how well company personnel use the system to manage the business that counts. In order to use the system, people must understand it. Hence the need for an intensive education program. No matter how good the system is, if the data used are inaccurate, the results will be poor. Computer-based systems are less forgiving of data inaccuracies than manual systems. Unless the company already has an accurate production system database, a major effort must be undertaken to improve and maintain accuracy. Of particular importance are the bill of material, routings and inventory records. Implementing MRP II represents one of the highest cost/ potential payback of any project undertaken in an organization. In order to be successful in implementing it, system should be ca refully planned and organized. The process of planning involves setting goals, selecting and developing methods for achieving those goals, and presenting the plan, as required to begin its execution. The process of organising consists of : Specifying the task to be performed; breakdown of the total task into manageable segments; establishing clear responsibilities and selecting people to execute the task. Two principal groups are formed to implement a MRP II system; the steering committee that will direct the organization's efforts, and the project team responsible for implementing the system at the operational level. One of the most important decisions should be taken while implementing the MRP II project is whether the company will purchase a software package for MRP II or develop and program its own inter- : nally. The company should look at their situation closely, and then should decide. Let's suppose a company decided to buy that xn -package, that company should obey some rules given below : - Determine the features wanted in the package, - Prepare a list of prospective software vendors, - Prepare a request for proposal and send it to the vendors under consideration, - Evaluate the proposals, - Decide which package to choose, based on the above analysis. In the last chapter öf my thesis, I tried to write about a MRP II package called PRISM. This package has been developed by MARCAM Corporation and it is a manufacturing control system which has been designed to meet the specific needs of the process and repetetive manufacturer, allows user to define model, and control all the manufacturing aspects of the business within one system. Utilizing defined resources, production models and schedule control, a new level of production and cost information can be available. Package consists of independent and interactive modules. Each module has its own master files, its own maintenance, report listing and inquiry programs. Some characteristics of the process manufacturers and detailed explanations of the modules will be given in chapter seven. Once the system is implemented, all the benefits will not be achieved immediately. It is important to keep track of improvements toward goals and to make sure that the system is operating as planned. The best way of doing this is to select a set of measures of performance, set a goal for each measure, set a tolerance level for each measure, and take these measures and report them at periodic intervals. Failure to meet the goal for three consecutive periods or deviation outside tolerance for one period should be investigated and corrective action taken before a more serious problem develops. - xm