A simulation based approach for reliability evaluation and optimization of time-dependent systems: A case study of production systems (barin plast company)

Abstract

Tahran-ran'da faaliyet gösteren Barin Plast irketi'nin güvenilirlik düzeyinin analizedilmesi ve geli³tirilmesidir. Bu i³letmenin ürünü, genelde ah³ap sanayiinde kullanlankenar bantlama makinesidir.Farkl sistemlerin güvenilirliklerinin de§erlendirilmesinde genellikle analitik yakla³mlarve simülasyon metotlar olmak üzere iki yakla³m kullanlr. Bu çal³ma kapsamnda incelenenproblem, analitik yakla³mlarn uygulanmasna izin vermemekte, bu nedenle bumetotlarn sonuçlar ile i³letmenin gerçek vaziyeti arasnda büyük farkllklarn olmasbeklenmektedir.Bu sebepten dolay, bu i³letmenin güvenilirlik düzeyinin de§erlendirilmesi için MonteCarlo simülasyonunun kullanlmasna karar verilmi³tir. Simülasyon modeli, kendi alanndagüçlü bir ürün olan Arena yazlm ile hazrlanm³tr. Sistemin güvenilirli§inin de§erlendirilmesindensonra, yedek bile³enlerin sisteme eklenmesi ya da mevcut makinelerindaha güvenilir olanlarla de§i³tirilmesi yoluyla i³letmenin güvenilirli§inin artrlmas amaçlanmaktadr.Yedek bile³enlerin yerle³tirilmesi ve sistem güvenilirli§inin optimum noktasnn bulunmas için bir takm metotlar vardr. Bu çal³mada yedek bile³enlerle donatlm³ sistemingüvenilirlik de§erlendirmesi için sezgisel bir model hazrlanm³ ve optimizasyon problemiçözülerek elde edilen sonuçlar kar³la³trlm³tr.Makine arzalanmalarna ait olaslk da§lmlarnn hazrlanmas için ihtiyaç duyulanve be³ yllk bir periyodu kapsayan arza senaryolarn gösteren veri i³letmeden teminedilmi³tir. ³letme için arzulanan güvenilirlik seviyesi 30 günlük bir periyot için %85'tir.

Reliability is an important factor to assure the productivity, and efficiency of a system in many industrial establishments. One should look for a higher level of reliability, for his company, to increase the properly working time of the system by reducing the chance of failure occurrence in the system and so on increasing availability of the system which means more efficiency and profit. The purpose of this study is to evaluate and improve the reliability level of Barin Plast Company (which is allocated in Iran, Tehran) based on available methods of reliability assessment and optimization. The product of this company is edge bandings which are mostly used in wood industries. Generally, there are two approaches to evaluate the reliability in different systems which are analytical and simulation methods. In this study, problem restrictions don't let us to implement the assumptions of analytical approaches, therefore there would be a big difference between the results of this method and real conditions of company. So, Monte Carlo simulation has been chosen to evaluate the reliability level of this company. The simulation model has been prepared by Arena software that is a strong tool in this area.After assessing the system's reliability, the main goal is to improve the reliability of company by adding redundant components to the system or replacing current machinery with better ones. There are some methods for redundancy allocation and finding the optimal solution for system's reliability. In this study a heuristic model has been prepared, for reliability evaluation of the system with redundant components, and the results are compared by solving the optimization problem. The required data to prepare the machinery failure probability distributions are provided by company in which they show the failure scenario of machinery for a period of 5 years. The desired conditions of company's reliability is 85 percent for period of 30 days.