M. Ing. / Reliability is basically the measure of performance, it is the probability that a system or component will perform its required task without failure under certain conditions for a given period of time [1]. As systems have become more complex in recent time the need for reliability within that system has become more and more important, safety, productivity and profit are three factors that have also demanded an increased level of reliability [2]. The reliability of an industrial gear unit comes from the reliability of all the individual components within the gear unit. Bearing lives are often the limiting factor of a gear unit and more often than not the lubrication becomes contaminated through insufficient maintenance practices, operational practices and harsh environments. This then results in the premature bearing failures within the gear unit. If the gear unit’s “health” can be monitored and imminent failures are known then the unit can be taken out of service and replaced or repaired prior to failure and during scheduled maintenance periods, this will then reduce overall repair costs and drastically reduce unscheduled maintenance time and cost.

Studien är utförd för att identifiera faktorer som påverkar materialflödet negativt i en tillverkningsindustri. På fallföretaget Gunnebo Industries observerades ett specifikt problemområde med fluktuationer som grundar sig i smidesmaskiners driftsäkerhet. Dessa skapar påföljder som försvårar materialhanteringen. Rapporten illustrerar sedan hur stokastisk modellering av maskinfel kan användas som ett indikationsverktyg. Resultatet påvisar en weibullfördelning för samtliga smidesmaskiner. Modellen kan användas för att finna potentiella förbättringsområden eller till och med för att utveckla implementerbara förbättringar. Den reflekterar över nuvarandetillstånd, likt värdeflödesanalys, men med fokus på maskiners pålitlighet. Dessutom diskuteras diverse faktorer som influerar modellen samt hur den i sin tur kan användas vid vidare forskning och analys. / The thesis is conducted on the basis of identifying negatively influencing factors on the flow of material within a manufacturing environment. At Gunnebo Industries the case study revealed a specific problem with fluctuations caused by machine reliability. The report illustrates how stochastic modelling of machine failure can be utilized as a tool of indication. The model can be used to uncover potential refinements regarding production and maintenance. It reflects on current state, complemented by what is attainable. Similarly to value stream mapping, but by emphasizing machine reliability. Furthermore, a discussion is formed regarding various interesting factors influencing the model, and how it in turn can be used in further research and analysis.