Categories: General
      Date: Aug  6, 2010
     Title: MIRCE Science Questions

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MIRCE Science Questions for 2018

Question 2018.1: Are Drones More Dangerous To Aircarft Than Birds? 

Question 2018.2: The pump type considered pumps 30 litres of water per minute. Assuming that the time to the occurrence of the first negative functionability event of a pump could be represented with an exponential probability distribution, with a mean value of 1000 hours, determine the amount of water pumped during the first 500 hours of continuous operation. In case of the failure of a pump, no additional actions are taken.

Question 2018.3: For the pump type considered in the question 2, determine the amount of water pumped during the first: 2000 and 5000 hours of continues operation.

Question 2018.4  The pump type considered pumps 30 litres of water per minute. Assuming that the time to the occurrence of the first negative functionability event of a pump could be represented with a Weibull probability distribution, with a scale parameter of 1107 hours and shape parameter of 3.75, determine the amount of water pumped during the first 500 hours of continuous operation. In case of the failure of a pump, no additional actions are taken. Compare the results with those obtained in the Question 2018.2, as both pumps have Extected Time To First Negative Event of 1000 hours.

Question 2018.5: The pump type considered pumps 30 litres of water per minute. Assuming that the time to the occurrence of the first negative functionability event of a pump could be represented with an exponential probability distribution, with a mean value of 1000 hours. The failure of a pump initiates immediate replacement for the pump with an new one. It is expected that the maintenance task taken could be represented with a exponential probability distribution with an expected value of 8 hrs.Determine the amount of water pumped during the first 500 hours of continuous operation and compare the results with the operation of the pump of the same type, considered in the question 2018.2, where the failures of the pump has not been rectified.

Question 2018.6:The pump type considered pumps 30 litres of water per minute. Assuming that the time to the occurrence of the first negative functionability event of a pump could be represented with a Weibull probability distribution, with a scale factor of 1107 hours and shape factor of 3.75 (mean time of 1000 hours). The failure of a pump initiates immediate replacement for the pump with an new one. It is expected that the maintenance task taken could be represented with a Weibull with a scale parameter of 9 hours and shape parameter of 2.7. Determine the amount of water pumped during the first 500 hours of continuous operation and compare the results with the operation of the pump of the same type, considered in the question 2018.4, as the expected time to failure and expected time to repair both pumps are identical.

Question 2018.7: Question 2018.6 considered the pump that is able to pump 30 litres of water per minute, and it asked to determine the amount of water pumped during the first 500 hours of continuous operation. Mathematically the life of a pump was defined with the following data:
•    the time to the occurrence of the first negative functionability event of a pump could be represented with a Weibull probability distribution, with a scale factor of 1107 hours and shape factor of 3.75 (mean time of 1000 hours).
•    the failure of a pump initiates immediate replacement for the pump with an new one.
•    the maintenance task taken could be represented with a Weibull with a scale parameter of 9 hours and shape parameter of 2.7.
However, MIRCE Science studies the physical motion of functionable systems types, which also includes the rules under which is operates. Hence, the rules that defined the following issues have not been addressed in the Q2018.6:
•    Number of spare pumps available
•    Working hours of maintenance teams
•    Amount of tools and equipment available,
•    Capacity of maintenance facilities
•    Quantity of technical documentations available at he site
•    Many other real in-service issues that impact the amount of work done by the pump during the continuous operation of 500 calendar hours.
Thus, determine the amount of the water pumped, assuming that there is an infinite quantity of all other resources but the maintenance teams, which for the purpose of this exercise work in two shifts (16 hours per day, 7 days per week). 

Archived MIRCE Science Questions

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A company has decided to develop a new control processor for a North Sea installation of a wind turbine. The processor will be based on equipment the company already has field reliability data for. It is envisaged that it will consist of the following three elements:

1. Fan, vaneaxial, whose Time to First Failure is defined by W(5000,5)
2. Data processor, whose Time to First Failure is defined by W(10000,1)
3. Mounting tray, whose Time to First Failure is defined by W(10000,7)

The three components are connected in series, from reliability point of view, and no maintenance activities are planned till the first failure of the control processor takes place.

The Solution Requirements
a) What is the Reliability Function of the Control Processor?
b) What is the Mean Time to First Failure of the Control Processor?
c) What is the probability of fault free operation for the first 6 months of continuous operation?
d) Given the difficulty in maintaining off-shore wind turbines, how much of an improvement in the intrinsic Mean Time to First Failure could be expected if another data Processor is added in a parallel configuration?

When asked to define the length of time a customer is going to wait for spare parts for a new type of equipment, the logistics support manager (who has spent seventeen years supporting similar equipment, made the following judgement:

a) Making use of the above data, determine the probability that a potential customer will receive the necessary parts within 3 hours of placing an order.
b) Also determine the proportion of customers whose demand for needed spares will be met within two weeks from the placing the order.

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