IARJSET ISSN (Online) 2393-8021 ISSN (Print) 2394-1588 International Advanced Research Journal in Science, Engineering and Technology ISO 3297:2007 Certified Vol. 4, Issue 3, March 2017 Copyright to IARJSET DOI 10.17148/IARJSET.2017.4317 76 A Study on Reliability Analysis of Haul Trucks A. Ramesh Kumar 1 & V. Krishnan 2 Head, Assistant Professor, PG & Research Department of Mathematics, Srimad Andavan Arts & Science College, (Autonomous), TV. Kovil, Trichy Assistant Professor, PG & Research Department of Mathematics, Jamal Mohamed College (Autonomous), Trichy Abstract: In this paper, we present the study of the two-parameter Weibull distribution theory and its parameters (shape β and scale α) using Weibull Probability Plotting. Using the failure data for haul trucks in operation at a marble quarry, we obtain the fatigue life equation by regression under different failure probabilities. Weibull distribution analysis for reliability and maintainability is showing a tendency of increasing failure rate, leaving room for decisions on reliability centered maintenance planning, machine improvements, optimal load and the need for review of data collection process. Keywords : Reliability, Weibull distribution, Availability, Maintenance, Monitoring. INTRODUCTION Reliability is the probability that parts, components, products and systems will perform the functions for which they were designed without damage underspecified conditions, for a certain period of time and with a given confidence level. Although reliability is an independent notion, reliability and the concept of quality are closely related. The quality of a product represents all properties that make it suitable for the intended use; reliability is the ability to keep product quality throughout the operation. In other words, product quality reliability is extended in time [22].Reliability engineering techniques provide theoretical and practical methods that the likelihood and ability of the parts, components, equipment, products and systems to perform the functions for which they were designed and built, during predetermined time, under specified and known levels confidence, can be specified in advance, designed, tested, proven even under conditions in which they were stored, packaged, transported and then installed, commissioned, monitored and information submitted by all involved and interested. The reliability of machinery is essential, particularly in quarries, since the breakdown of any machine would cause an unpredictable loss or damage [14]. Therefore, it is obvious that the reliability of such equipment would have considerable impact, not only on production, but also machine life and potentially on human life. Prevention is better than cure. Instead of allowing the occurrence of failure and suffering from loss or damage of assets and environment, it is always worthwhile forestalling the occurrence. To operate in quarries with reduced number of failures, because of the harsh environment, the machines must be maintained to exhibit high reliability. The maintenance planning of equipment hence requires the orientation of reliability at every stage of its life. The present study is on effort in this direction that can provide some guidelines while planning the maintenance activities with an orientation to reliability. The most difficult part of this process is the acquisition of trustworthy data. It is known that no amount of precision n the statistical treatment of the data will enable sound judgments to be made based on invalid data. 1 Problem Formulation Reliability is characterized by four concepts: probability, performance achieved, operating conditions and duration. Operational reliability is obtain parameter estimates that will help us to infer the reliabilities of the concerned machinery; and thus are able to compare them determined in real operating conditions. In some cases non-economic laboratory experiments, the main source of data collection, are not feasible. Experience in the field is recommending the selection of a group of beneficiaries, by category of use, operating conditions, etc. and systematic tracking performance of products through group reliability. This information is collected through direct reports of the interventions to address the nonconformities. Information processing is done by one of the methods available. Operational reliability is divided in two parts: functional and technological. Functional reliability is known as the operational safety concern matters relating to the operation of the system in terms of primary kinematics [2]. Technological reliability concerns with keeping within the limits of working parameters values. E.g. for a hydro pneumatic cylinder-piston engine, functional reliability is achieved during movements for which the engine was developed and designed; technological reliability means keeping the speed of travel, breaking times, force to the working body. 1.1 Reliability Indices The basic reliability indices, as parameters which express reliability from a quantitative point of view, are being expressed by: the good operating probability, reliability function, R(t); probability of deterioration, non- operation reliability function, F(t); probable density of deteriorations, f(t); intensity or rate of deterioration, z(t); mean time of good operation, MTBF; mean time for repairing operations, MTR; rate of repairing operations, μ. Limit failure rate is the ratio of the probability that a device be damaged within the given time estimated (t, t+dt) and the size of the sub-interval dt, since it tends to zero, provided that it is part of the devices that were in good condition early in the process. Any product lasts and