Reliability Engineering
Reliability Engineering
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Reliability Engineering
• What is Reliability Engineering? • Role of Reliability Engineering (Technical Support) • Reliability Engineering Activities – Maintenance Prevention – LCC Analysis – Proactive Maintenance (FPA, RCFA, Specification for New/Rebuilt Equipment, etc.) – Capital Equipment Replacement – Economic Evaluation/Justification Analysis in R&M Investments • Other Analytical Techniques for Improvement • Elements of a Reliability Improvement System
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What is Reliability?
• “The RELIABILITY of an item/system is the probability that the item/system performs a specified function under specified operational and environmental conditions at and throughout a specified time.” Quantitatively, reliability is the probability of success. Usually expressed as Mean Time Between Failures (MTBF) • “A collection of planned activities (established through formal and informal management systems) that are effectively working together to prevent loss of system function.” This second definition is a managed approach to maintain the reliability of system functions. Both definitions refer to the system and maintaining the functionality of the system
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Definitions
• Maintainability: The ability of an item, under stated conditions of use, to be retained in, or restored to, a state in which it can perform its required function(s), when maintenance is performed under stated conditions and using prescribed procedures and resources. Expressed as Mean Time To Repair (MTTR). • Availability: Is the probability that a system is available for use at a given time- a function of reliability and maintainability. It is operating time divided by load time, which is the available time per day minus the planned downtime . • Failure: The termination of the ability of an item to perform its required function.
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Inherent Availability
Ai = MTBF MTBF + MTTR
Inherent availability considers only corrective maintenance in an ideal support
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Reliability Engineering
• What is Reliability Engineering? • Role of Reliability Engineering (Technical Support) • Reliability Engineering Activities – Maintenance Prevention – LCC Analysis – Proactive Maintenance (FPA, RCFA, Specification for New/Rebuilt Equipment, etc.) – Capital Equipment Replacement – Economic Evaluation/Justification Analysis in R&M Investments • Other Analytical Techniques for Improvement • Elements of a Reliability Improvement System
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1
What is Reliability?
• “The RELIABILITY of an item/system is the probability that the item/system performs a specified function under specified operational and environmental conditions at and throughout a specified time.” Quantitatively, reliability is the probability of success. Usually expressed as Mean Time Between Failures (MTBF) • “A collection of planned activities (established through formal and informal management systems) that are effectively working together to prevent loss of system function.” This second definition is a managed approach to maintain the reliability of system functions. Both definitions refer to the system and maintaining the functionality of the system
3
Definitions
• Maintainability: The ability of an item, under stated conditions of use, to be retained in, or restored to, a state in which it can perform its required function(s), when maintenance is performed under stated conditions and using prescribed procedures and resources. Expressed as Mean Time To Repair (MTTR). • Availability: Is the probability that a system is available for use at a given time- a function of reliability and maintainability. It is operating time divided by load time, which is the available time per day minus the planned downtime . • Failure: The termination of the ability of an item to perform its required function.
4
2
Inherent Availability
Ai = MTBF MTBF + MTTR
Inherent availability considers only corrective maintenance in an ideal support