Reliability Centered Maintenance. Reliability Engineering and Asset Risk Management

ANSWER TO QUESTION 1.

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b) The reliability target of achieving 10,000hrs MTTF for the system MTTF = 1/ λ

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Now calculating to get λτ = 100 can be achieved by adding redundancy to the transmitter

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Reason for adding the redundancy to the transmitter is because it has the higher failure rate.

ANSWER TO QUESTION 2.

CONSIDERING THE FIRST SENSOR

The probability of a fault occurring = 0.02 Probability of detecting the fault = 0.95 The probability of false alarm = 0.10 Let A = Report Fault Let В = Actual fault

Let В/A should be that a reported fault has actually occurred.

Then the probability that a fault has actually occurred and is reported by the first sensor is = P (B/A)

Using Bayes' Theorem:

p (B/A) = p (A/B) * P(B)/P(A/B)*P(B) + P(A/B')* P(B)

p (B/A) = 0.02 * 0.95/ (0.02*0.95) + (0.1*0.98) p (B/A) = 0.019/0.117 p (B/A) = 0.1624

CONSIDERING THE SECOND SENSOR

The Probability of a fault occurring = 0.02 The Probability of detecting a fault is = 0.90 The Probability of false alarm = 0.05 Let A = Report Fault Let В = Actual fault

Let B/A be that a reported fault has actually occurred

Then, the probability that a fault has actually occurred and is reported by the second sensor = p (B/A)

Using Bayes' Theorem:

p (B/A) = p (A/B) * P(B)/P(A/B)*P(B) + P(A/B')* P(B)

p (B/A) = 0.02 * 0.90/ (0.02*0.90) + (0.05*0.98) p (B/A) = 0.018/0.067 p (B/A) = 0.2687

ANSWER TO QUESTION 3

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RELIABILITY-CENTERED MAINTENANCE AND ITS APPLICATIONS TO

OFFSHORE WIND TURBINES

1. INTRODUCTION

For so many years, maintenance have been experiencing trends of transitions from one stage to another. These stages of transformational procedures are due to the fact that all assets that are put into operation requires essential maintenance so as to improve in the availability of the system and also to achieve efficient and effective functionality of the system. Maintenance must be done to ensure a system is available and functioning well thus utilising the system optimally and minimising cost (Moubray,1997). This paper is going to focus on a maintenance method that provides reliability to a functional system and in a cost-effective manner known as Reliability centered maintenance technique. According to Moubray (1997) RCM is "a procedure that is used to ascertain what should be done to make sure that all component of a system continues to perform its intended function and in the way its user wants it to operate in its current operating circumstance"

RCM is simply referred to as the idea of considering the lasting reliability of system. It includes coming up with ideas and ways of maintaining the system, and to make sure it is reliable throughout its expected life period. It encompasses adding weight to the choice of systems which is recognised to be dependable and sustainable and for which logistic sustenance is most gladly delivered. เท practice this often means choosing systems that are readily accessible off-the-shelf and which are since commonly used. It also includes examining for reliability and acceptable installation at the time of acquiring the asset. Key issues are system harmony, reliability and maintainability, assessment, and acceptance testing (Nicholas A.J,2010).

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