EXAMINATION OF THE EFFECT OF SMED METHODOLOGY ON THE SETUP TIME AND UNIT COST: APPLICATION IN THE STEEL BAR PEELING PRODUCTION LINE

SMED UYGULAMASININ AYAR SÜRESİNE ve BİRİM MALİYETE ETKİSİ: KABUK SOYMA PARLAK ÇELİK ÜRETİM HATTI UYGULAMASI

Abstract

Competition is one of the most important factors in determining the independence of product prices. Increasing competition conditions cause sales prices of products and services not to be determined by enterprises. On the other hand, competition forces companies to seek alternative methods and tools.Production companies increase their investments in production technologies in order to increase the efficiency of the process. The product quality is increased and the production times are shortened by the effect of these investments. In spite of the positive results of the investments, operating costs have been negatively affected and production costs have increased significantly.The two factors that affect the level of companies’ profitability are the sale price and conversion costs. The profitability of the companies decreased due to the determination of the sales price in the market conditions and the increase in the operating costs. As a result, it is necessary to manage the operating costs better in order to increase the level of profitability of the enterprises and to continue the operational activities.The companies initially focused on reducing department cost items. Due to the limited results, they realized that the actual losses were in the production process. It is important how effectively the unit time is used in a process where production costs are high. Therefore, process-oriented thinking has gained weight and companies have begun to try to improve the production process.The problem of uncontrollable production processes in traditional production enterprises is that the number of non-value-added activities and their weight are high. Actual production time is low due to the high number of chronic problems such as failure, adjustment and waiting. On the other hand, the total adjustment period has increased due to changing customer expectations, increasing product variety, and decreasing demand size. As a result, the actual production time is further reduced.One of the most important posture losses in uncontrolled production processes is the adjustment and preparation processes. Under changing conditions, the adjustment time has become more important. The SMED methodology is one of the methods frequently used to improve the setup process. It is a lean manufacturing tool that focuses on the creation and development of a systematic setup process with the aim of reducing the losses of enterprises.The SMED Methodology contributes to the adjustment and improvement of the machinery or equipment to be performed with minimum setup time. In this way, it is possible to reduce the time of preparation between two orders in production processes and reduce the size of order parties and reduce stock costs.At the end of SMED applications, it is generally concerned with how much the unit setting times are reduced. However, as well as examining the effect of the results of the application on the unit set-up time, it is necessary to examine the effect of the results on the total efficiency of the equipment and the unit cost of the equipment. The fixed costs per product will be reduced, depending on the increase in production quantity per unit time. Therefore, the reflection of SMED applications on unit cost should be evaluated in order to reflect the results to the level of pricing and profitability.The aim of this study is to investigate the effect of SMED applications on total production times and unit costs. For this purpose, a SMED application study was carried out in the production line of a bright steel company in Kocaeli. The study was evaluated in two separate stages as measuring the effect on the production time and measuring the effect on the unit cost after the improvement of the process.OEE (Total Equipment Effectiveness) was used to evaluate the effectiveness of production vehicles and to prioritize the machinery or equipment to be improved. OEE is a key performance key that allows the production line to be evaluated based on availability, performance and quality. In the study, prioritization of the three main product lines of the company was evaluated according to OEE calculated based on 2017 production data. According to the result of the evaluation, it was decided to work on the peeling machine.The SMED methodology in the selected production line has been implemented in four stages: analyzing the current situation, separating the internal and external adjustment processes, converting the external setting operations to internal setting and improving the steps of the process.On the production line, there are two types of settings: production changeover and cutting tool change. During the year, the total production change and cutting tool change were 20250 min and 5072 minutes. The application number of the setting types is 810 and 317. Table 4 shows the adjustment process steps of the setup types. According to the table, the production and blade change settings are average at 29 and 17 minutes.In the second phase of SMED implementation, the internal and external adjustment process are separated. However, the process of feeding the raw material to the production line has been turned into an external setting. For this reason, the third and fourth stages were implemented together, and both internal adjustment processes were transformed into the external adjustment process, and both process steps were improved.As a result of the SMED application, the internal set up times for the production and blade change adjustment processes were reduced to 8.5 minutes and 6 minutes. When the total number of setup in the year is not changed, the total set up times has been reduced to 8787 minutes. Accordingly, the total production time increased by 16535 minutes. In total production time, availability increased by 7.45%.In order to examine the effect on production unit costs, the FTM (Activity Based Costing) system has been established in the company. The FTM system is a cost management tool that can

Özet

Amaç: SMED yönteminin ayar sürelerine ve birim zaman maliyetine olan etkisini araştırmaktır.Yöntem: Ayar sürelerinin iyileştirilmesinde SMED metodolojisi kullanılmıştır. Elde edilen sonuçların, birim maliyete olan etkisi FTM sistem ile değerlendirilmiştir.Bulgular: Çalışma sonucunda iki ayar sürecinde 66% ve 62,5% iyileştirme sağlanmıştır. Ayar sürelerinde ve diğer duruşlarda sağlanan 1 dakikalık iyileştirme, birim maliyetlerde 0,0000514 TL azalma sağlamaktadır. Toplam ayar sürelerindeki iyileştirmeler, birim maliyetlerin 0,85 TL azaltmıştır. Sonuç: SMED uygulamalarında elde edilen zaman kazançlarının yanı sıra bu kazançların üretim birim maliyetine nasıl bir etkide bulunduğunun tespit edilmesi için, etkilerin maliyet sistemi üzerinden izlenmesi gereklidir.