Sistem yaklaşımıyla üretim planlama ve kontrol

Abstract

Bu çalışmada "Sistem Yaklaşımıyla Üretim Planlama ve Kontrol" kavramı ele alınmaktadır. Üretim programlama konusunda oluşabilecek problemler tanımlanmakta, bunların çözüm yolları çeşitli modelleme yöntemleri ile açıklamaya çalışılmakta, tasarımların nasıl olması gerektiği ve işletmede nasıl uygulanacağı incelenmektedir. Birinci bölümde üretim kavramı, üretimin çeşitleri ve amaçları konusunda bilgi verilmekte ve genel hazırlık bilgileri sunulmaktadır. İkinci bölümde, üretim planlama ve kontrol kavramı, planlama faaliyetleri ve bunların niteliği hakkında ayrıntılı bilgi verilmektedir. Üretim programlama yaklaşımlarından "Ana Üretim Planlaması" nın detaylı olarak incelendiği üçüncü bölümde, uygulamada karşılaşılan sorunlar belirtilmekte ve belirli kriterlere bağlı olarak gözönüne alınan matematiksel çözüm yöntem ve kuralları incelenmektedir. Ayrıca, bu konularda geliştirilmiş etkin ve iyi sonuçlar verebilen be lirli modellemelerden bahsedilmektedir. Dördüncü bölümde, her disiplini sistem yaklaşımı açısından incelemenin yararı gözönünde tutularak, temel Sistem Analizi kavramları verilmeye çalışılmakta ve sistem yaklaşımıyla ÜPK kavramı üzerinde durulmaktadır. Son bölümde ise, alçak ve orta gerilim güç kabloları, tesisat kabloları ve Emaye Bobin Teli üretimi yapan bir işletmenin Üretim Planlama ve Kontrol sistemi hakkında ayrıntılı bilgi verilmektedir

In today's economic system, firms producing items or services have a fairly wide profitable place. They produce these items in a specific management system which can realize manufacturing in the best possible ways. Chapter one consists of production concepts, production types, the importance of production scheduling in Industrial Engineering and Industrial Engineering studies which must be done before production scheduling. Production systems combine materials, labour and capital resources in an organized way with the objective of producing some good or service. Production systems may occur in factories, banks, offices, retail stores, hospitals, etc. In all instances, some input to the system is being processed within the system to produce a good or service as an output. In this study, we are dealing within the operations phase. In general, manufacturing system can be divided to two basic structures as continuous systems and intermittent systems. Production planning and control techniques are used in both of the systems. Production planning and control concept have been considered in chapter two with a general structure first objective of production planning and control system is maximize the profit, other objectives may be increasing quality levels and performing better inventory investments. Scheduling and sequancing decisions are the short-run planning and control activities. They can be realized in operations level and performed by labour force at the shop. Scheduling and control decisions appear in two different topics. Aggregate planning and scheduling decisions which set basic production rates and employment levels in the short run and for a reasonable time horizon in the future. In the scheduling and production control, feasible schedules must be worked out which ars compatible with the aggregate planning decisions already made and which make the best use of available men and equipment. Once scheduled the progress and flow of work must be controlled, through information feedback and appropriate action, kle can say that the sequencing problem is only a part of the overall problem of controlling the flow of orders in a system. The production planning of required processing and routing requirements, material procurement and other planning precedes the sequencin problem and follow up or VI control to insure on time completion of orders follows the sequencing problem. Chapter three consists of Main Production Planning. In this chapter, mathematical approaches and theoretical studies which can solve problems effectively has been discussed. Main Production Planning is a process of middle-run planning which is between 3-12 months. Scheduling theory is concerned primarily with mathematical models that relate to the scheduling function. The development of useful models and techniques has been the continuing interface between theory and practice. The models that are used in the Main Planning can be classified into two groups : a) Static production planning, b) Dynamic production planning. It's accepted that the demand doesn't change for the static production plannn But, demand can be different for the dynamic production planning. Mathematical methods are usually used to solve these problems. Linear programming method is very important among these methods. Linear programming problems are related the resources that can be limited, like labour, materials, machine, etc. and using of these resources. In other meaning, linear programming problems are distribution problems. Resources are distributed different processes to maximize the profit and to minimize the cost. Several static and dynamic programming models have been improved to solve the decision making problems in the production systems. In the last two part of third chapter, these models are explained. In general, there are 3 decision making problems are studied in the production systems : i) Multipraducts systems, ii) Multipracesses systems, iii) Multifoundatian systems. When the demand changes according to the period, dynamic production planning is used. It's accepted that the demand of every period is known. But the demand can be different in every period, in that case planning problem is called "dynamic". In this type planning, managers have to adjust the inventory level and toe working capacity according to the changeable demand level. In this study, production planning and control is explained with the system approach. So, in chapter four, there is sorae information about system analysis. System is a group of things or parts related or combined in such a way as to form a unified or Vll complex whale. The tdard of "system" can be used almost in every area of life, nowadays. But, its meaning is different for every part. The definition, members, importance and principles of system analysis are explained in chapter four. Strategy can be defined as the situation that a company wants to reach in a certain time. The process of strategic planning consists of two stages : 1. Development of the strategy 2. Description of the periods and costs of stages necessary for the realisation of the strategy. In planning, system approach begins with the evaluation of the strategic planning as the main frame. Strategic plans are objective but not detailed. The plan which determines long term targets does not include options to reach these targets. However, within the frame of long term targets short and medium term targets can also be determined. In other words, the strategic plan comprises main elements which are fundamental in the preparation of the two short «term plans; "Development Plan" and "Operational Plan". Development plan covers expansion and growth of the business. Operational plan, on the other hand, sets the targets of operational activities for a period of one year. When system approach within the frame work of planning process is analysed, it will be seen quite clearly that studies under taken throughout the planning process depend on the availability and assessibility of critical inputs. In no enterprise, without necessary information system and inputs derived from it, such a plan can successfully be prepared. The information used in the planning can be classified as : 1. Environmental information, 2. Information related to competition conditions, 3. Information at the level of the enterprise. Planning starts with the acquisition and analysis of information about production resources and the products to be produced. In order to reach the targets whicn are set as a result of the evaluation of these inputs, resource utilisation activities are determined in a comprehensive program. In other words, production plan sets subsequent targets for various production sections as time intervals determined previously. Reaching these subsequent targets results in the accomplishment of the final goal which is the main target. Operations are carried out in an order and according to the details which set previously in the production plan. Vlll On the other hand, control initiates and supervise the operations uith the aid of acquired information and feedback systems. At the stage of controlling, it may be necessary to make certain changes and rearrangements in subsequent targets in order to guarantee a success in the final target. A demand report is a prerequisite in every production planning operation, since this can have significant effects on production capacity and production scheduling. There are three main terms according to the periods covered. Long term, medium term and short term. Long term planning covers a period of one to five years. It basically depends on technological evaluation and has major effects on global business policy. Long term planning is not covered in this study dueto the fact that the decisions of high level management and management tendencies are the major criteria in setting long term planning. Medium term planning (main planning), on the other hand, covers a period of one to twelwe months and short term planning (detailed plan) covers operations to be carried out immediately. The operations of the main production planning mainly establish the speed and capacity of production, necessary man power, volume of the completed products, and analyse the need for overtiming and the need for subcontracting. Three major decisions are taken in the planning of operations : - Determination of the operations necessary, - Determination of the job stations in which operations take. place, - Determination of the order of operation. In the last chapter, a detailed analysis of production, planning and control of a wire producing company is made. Main products of the company are low and medium voltage power cables, installation cables and enamelled capper wires, etc. Firstly, the basic knowledge about the company is made, in this study. Then the production activity of the company is explained. Further, the production planning and control system which is current in the company, its running and the proposition about how we can eliminate the problems caused by this system are made. Production flaw charts, computer programme and its print which are used in the company can be examined in the addition part. In scheduling problem, two kinds of feasibility constraints are found. First, there are limits on the capacity of available resources. Second, there are technological restrictions on the order ix in which tasks can be performed. For solving scheduling problem two question must be answered : 1. Which resources will be assigned to perform each other, 2. When will each order be performed. The theory of scheduling also includes a variety of techniques that are useful in solving scheduling problems. The selection of an appropriate technique depends on the complexity of the problem, the nature of model, and the choice of a criterion as well as other factors. In many cases it might be appropriate to consider several alternative techniques. In today's economic system, the biggest problem for companies is limited resources. These resources can be money, material, labour, etc. Managers are dealing with profit maximization and cost minimization under these conditions. Managers benefit from these techniques in their studies. They know that production planning and control is the best concept to reach their aim.