Toplam Verimli Bakım Ve Kordsa'daki Toplam Verimli Bakım Uygulamalarının Değerlendirilmesi

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 1997Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 1997TVB, üretim sistemlerinde sıfır ekipman duruşu ve sıfır kalite hatasını hedefleyen bir bakım sistemidir. Altı büyük kayıp olarak adlandırılan ;. Arıza kayıpları. Hazırlık kayıpları. Ayar kayıpları. Boşta çalışma ve küçük duruş kayıpları. Hız kayıpları. Kalite kayıpları' nın ortadan kaldırılmasını amaçlar. TVB, altı büyük kaybı ortadan kaldırabilmek amacıyla, altı önemli faaliyeti içerir.Bu faaliyetler şunlardır :. Üretim, bakım ve mühendislik departmanlarınca organize edilen proje grubunun, altı büyük kaybı ortadan kaldırması. ( Ekipman etkinliğinin maksimize edilmesi ). Bakım departmanının planlı bakım faaliyetlerini yürütmesi.. Mühendislik hizmetleri departmanının önleyici mühendislik faaliyetlerini yürütmesi.. Ürün tasarım departmanının imalatı kolay ürün tasarım faaliyetlerim yürütmesi.. Yukarıdaki çalışmaların eğitim ile desteklenmesi. Bu çalışmada tüm bu faaliyetler ayrıntıları ile ele alınmış, geniş bir içeriğe sahip olması ve pek çok yeni konuyu bünyesinde barındırması nedeniyle bazı kısımlar özet olarak verilmiştir. Tez iki kısımdan oluşmaktadır. Birinci kısımda, TVB tanım, tarihçe ve hedefleri ele alındıktan sonra, TVB'nin ana konulan olan, altı büyük kaybın ortadan kaldırılması, kullanıcı (otonom) bakım, planlı bakım ve erken ekipman yönetimi konularına yer verilmiştir. ikinci kısımda ise, ülkemizin önde gelen firmalarından olan KORDSA'daki TVB uygulamalarının değerlendirilmesi yapılmıştır. KORDSA, ülkemizin tek ve ilk, kord bezi ve endüstriyel bez üreten firmasıdır. KORDSA' da TVB uygulamaları 1994 yılında başlatılmış ve halen sürdürülmektedir. Bu süre içinde şu sonuçlara ulaşılmıştır :. Arıza sürelerinde ortalama %38' lik azalma.. İM arıza arasındaki ortalama sürede %175'lik artış.. Arızalanan ekipmanın ortalama devreye giriş süresinde %41 ' lik azalma.. Bakım maliyetlerinde %4 artış.. Bakım malzemesi ortalama stok seviyesinde %33 ' lük azalma.. Prosesler arası stok seviyesinde %35'lik azalma.. Personel eğitim saatlerinde %45'lik artış.Total Productive Maintenance (TPM ) is a new approach which is based on more effective use of equipment. Production equipment has become unmacginably sophisticated. We see equipment for automation, such as robots and unmanned production ; we also see equipment for superprecise processing of micron - size objects and processing that requires speeds, pressures, and temperatures challenging current technology. TPM, which is organizes all employees from top management to production line workers, is a companywide equipment maintenance system that can support sophisticated production facilities. The dual goal of TPM is zero breakdowns and zero defects. When breakdowns and defects are eliminated, equipment operation rates improve, costs are reduced, inventory can be minimized, and as a consequence, labor productivity increases. Of course, such results cannot be achieved overnight. It takes an average of three years. In early stages of TPM, the company must bear the condition and educating personnel about equipment. The actual cost depends on the quality of the equipment and the quality of maintenance. As productivity increases, however, these costs are quickly replaced by profits. For this reason TPM is often referred to as "profitable PM' A complete defination of TPM includes the following five elements : 1. TPM aims to maximize equipment effectiveness. 2. TPM establishes a through system of PM for the equipment's entire life span. 3. TPM is implemented by various departments (engineering, operations, maintenance) 4. TPM involves every single employee, from top management to workers on the floor. 5. TPM is based on the promotion of PM through motivation management : autonomous small group activities. To achive overall equipment effectiveness, TPM works to eliminate the "six big losses" that are formidable obstacles to equipment effectiveness. They are ; 1. Breakdowns 2. Set up times 3. Adjustment times 4. Idling and minor stoppages 5. Recuced speed 6. Process defects XV According to the Japanese Idustrial Standarts (JIS ), "a failure results in loss of a standart function in a certain object (e.g., system, machine, part)." This "loss of a standart function" indicates that machine failures are not limited to unexpected breakdowns that lead to a complete stopage. Even when equipment is running, deterioration can cause various losses, such as the loss of a standart function, longer and more difficult setup/adjustment, frequent idling and minor stoppages, and reduction in processing speed and cycle time. Such losses must be treated as failures. Unexpected breakdowns with complete stoppage are called "function - losses failures " while those involving equipment deterioration despite continued operation are called "function - reduction failures." Breakdowns represent the tip of the iceberg. We tend to become overly concerned with breakdowns are serious defects because they are so obvious, and there certainly are cases in which a single defect causes a breakdown. Small defects, however, such as dirt, dust, abrasion, loosening, scratches, and warping - which may seem insignificant on their own - are the real problem. These small defects can suddenly become large. Sometimes they overlap to create a stronger effect, triggering both function - loss and function - reduction failures. As the saying goes, "even one match can cause a fire," so it is important to stamp out defects while they are small. This is fundamental concept behind preventive maintenance. Defects that go undetected and untreated are called "hidden defects." If they remain untreated, they will trigger breakdowns. Therefore, it is important to expose hidden defects and restore optimal conditions. To eliminate failures we must expose hidden defects and treat equipment before it breaks down. The following five concrete countermeasures help eliminate failures : 1. Maintainig well - regulated basic conditions (cleaning, lubricating, and bolting ) 2. Adhering to proper operating procedures 3. Restoring deterioration 4. Improving weakness in design 5. Improving operation and maintenance skills To ensure that simple procedures are performed thoroughly, both the operations and maintenance departments must understand each other's role and cooperate, like the wheels of a car. They must be willing to adjust their points of view and behavior and fulfill their respective duties. Everyone involved with equipment operation or maintenance must work eliminate failures. TPM consists of three stages. They are preparation stage, implemantation stage and stabilization stage. XVI In the preparation stage, a suitable enviroment is created by establishing a plan for the introduction of TPM. There are five steps in the preparation stage. They are ; 1. Announce top management decision to introduce TPM 2. General TPM education 3. Create organizations to promote TPM 4. Establish basic TPM policies and goals 5. Formulate master plan for TPM development TPM is implemented through four basic TPM development activities : 1. Improve effectiveness of each piece of equipment 2. Develop an autonomous maintenance program 3. Preventive maintenance 4. Conduct training to improve operation and maintenance skills 5. Develop early equipment management program The final step in the TPM development program is to perfect TPM implementation and set even higher goals for the future. Autonomous maintenance by operators is a unique feature of TPM ; organizing it is central to TPM promotion with in the company. The longer a company has been organized, the harder it is to implement autonomous maintenance, because operators and maintenance personnel find it diffucult to let go of the concept : " I operate - you fix." Operators are used to devoting themselves full-time to manufacturing, and maintenance personnel expect to assume full responsibility for maintenance. Such attitudes and expectations cannot be changed overnight, which is one of the reasons why it typically takes three to four years to progress from the introduction of TPM to its full implementation. In promoting TPM, everyone from top to bottom in the organization must believe that is feasible for operators to perform autonomous maintenance and that individuals should be responsible for their own equipment. In addition, each operator must be trained in the skills necessary to perform autonomous maintenance. Autonomous maintenance consists of seven steps. They are ; 1. Initial cleaning 2. Countermeasures for the causes and effects of dirt and dust 3. Cleaning an lubricating standarts 4. General inspection 5. Autonomous inspection 6. Proces quality control 7. Full autonomous maintenance Audits of circle activities and equipment by supervisors and staff play an important role in the succesful development of an autonomous maintenance system. To conduct them xvu effectively, supervisors and staff must understand the work - palace enviroment thoroughly ; they must provide the circles with appropriate instructions and encouragement to give workers a sens of accomplishment as they complete each step. Scheduled (preventive ) maintenance carried out by the maintenance department must be coordinated with the autonomous maintenance activities of the operations department so the two departments can function together like the wheels of a car. Last three section of this study introduces TPM implementation in KORDSA. KORDSA is the cord tire and industrial fabric producer. KORDSA AS. was founded in 1973 as the first and last cord fabric and industrial fabric production industry of Türkiye. With its 28.000 tons of tire cord fabric and 5.000 tons of industrial fabric capacity, KORDSA is a leader in the sector. KORDSA offers to the world markets various types of tire cord fabrics, conveyor belting fabrics, chafer fabrics, polypropylen liners, single cords and other various types of industrial fabrics. The quality concept embedded in the company culture since 1989 has passed through several stages and finally materialized itself as " ISO 9001 QUALITY CERTIFICATE"."TOTAL QUALITY MANAGEMENT" system was adopted in 1995 and KORDSA has been awarded the "NATIONAL QUALITY AWARD" by TUSIAD KALDER along with the "SUPLIER OF THE YEAR" prize by Pirelli -Tr and Brisa in 1996. KORDSA introduced the TPM program in 1993. TPM is started with preparation stage. In the preparation stage a suitable enviroment was created. The preparation activities are ; 1. Announcing top management decision 2. TPM education 3. Creating TPM organization 4. Establishing basic TPM policies and targets 5. Formulating TPM master plan After the preparation stage, TPM implementations were started. TPM implemantation was heavily concentrated on autonomous maintenance program. It was through that beakdowns would be decreased in volume by autonomous maintenance practices after having six big losses. The other losses were excluded from the TPM program. The first four steps of the autonomous maintenance program were completed on some machines, and still in progress on the others. These steps were taken under autonomous maintenance program coverage ; XVlll .Initial cleaning : Operators develop an interest in and concern for their machines through cleaning them throughly. Operators learn that cleaning is inspection. They also learn basic lubricating and bolting techniques and become skilled in detecting equipment problems. 2.Countermeasures for the causes and effects of dirt and dust : The more diffucult it is for the individual to perform initial cleaning, the stronger will be his desire to keep the equipment clean and thus, to reduce cleaning time. Measures to eliminate the causes of dust, dirt, chips, and so on, or limit scattering and adherence (by using covers and shields ) must be adopted. If a cause cannot be removed completely, more efficient cleaning and inspection procedures must be disigned for the problem areas. 3. Cleaning and lubricating standarts In steps 1 and 2, operators identify the basic conditions that should apply to then- equipment. When this has been done, the TPM circles can be standarts for speedy and effective basic maintenance work to perevent deterioration, cleaning, lubricating, and bolting for each piece of equipment. 4. General inspection Steps 1 through 3 are carried out to prevent deterioration and control the basic conditions of equipment maintenance - cleaning, lubricating, and, bolting. In step 4, operator attempt to measure deteriotion with a general inspection of equipment. Morover, in working to restore the equipment to good operating conditions, the operator's equipment competence is increased. General inspection traing must be carried out one category at a time, beginning with skill development. Its effectiveness is audited and reinforced with additional training and pratical applications. This cycle of training, application, auditing, and modification is replaced for each inspection category. This fourth step may take along time to complete, because all operators must develop the ability to detect abnormalities. It is the best method to produce competent operators, however, so this step should not be rushed. Positive results cannot be achieved until each worker acquires all the necesary skills. It is estimated that the TPM program at KORDSA will be completed in 2001. The results in this practice have been very successful, and the number of failures has dropped by 50% since the beginning of the program. Overall Equipment Effectiveness (OEE ) has been lifted over 85%, the ideal volue of OEE. İt is very necessary to include the other five losses that were disregarded in the TPM program in order to increase the value of OEE within the company practices.Yüksek LisansM.Sc