What is System Reliability? - Basic Concept & Intuitive Explanation of Equipment Reliability

Summary

This lecture introduces the concept of reliability in an industrial and technical context. It defines reliability as the probability that a machine will perform its intended function without failure under specific conditions and time intervals. Key factors influencing reliability include operating conditions, time duration, and the inherent probability of failure. The lecture emphasizes that reliability is expressed as a percentage and depends on how long and under what conditions a machine operates. The session concludes with an introduction to the mathematical aspects of calculating reliability in future lectures.

Takeaways

• 😀 Reliability refers to the ability of a machine to perform its function without breaking down, under specific conditions and time intervals.
• 😀 In technical and industrial contexts, reliability is defined as the probability of failure-free performance under stated conditions.
• 😀 Reliability is dependent on three key elements: probability, conditions, and time.
• 😀 Reliability is a probabilistic measure, typically expressed as a percentage chance of an item performing without failure.
• 😀 The reliability of a machine can vary depending on the conditions in which it operates. For example, a car is more reliable on a paved road than on rough terrain.
• 😀 The duration of operation influences reliability. A machine may have a higher chance of failure over extended periods or under prolonged conditions.
• 😀 For example, a car has a 75% chance of running on rough terrain for 10 hours without breaking down; this statement includes the three key elements of reliability: probability, conditions, and time.
• 😀 The United States military standard on maintenance and reliability is one of the earliest comprehensive references on the topic.
• 😀 Reliability is an essential concept in industrial maintenance, where it is used to assess and improve machine performance over time.
• 😀 The next step in understanding reliability involves looking at the mathematical side, which includes how reliability is calculated.

Q & A

What is the general meaning of reliability in everyday language?

In everyday language, reliability refers to the quality of being able to be trusted or believed because something works or behaves well, without breaking down.

How does reliability differ in an industrial and technical context?

In an industrial and technical context, reliability is defined as the probability that an item can perform its intended function for a specified duration under certain conditions, or the duration of failure-free performance under stated conditions.

What is the United States military standard on maintenance and reliability?

The United States military standard on maintenance and reliability defines reliability in two ways: as the probability of failure-free performance under specific conditions, and as the probability that an item can perform its intended function for a specified interval under stated conditions.

What are the three important elements to understand about reliability?

The three important elements of reliability are: 1) It is expressed as a probability (percentage chance). 2) It depends on the conditions under which a machine is operating. 3) It is time-bound, meaning it depends on the duration of time a machine operates.

How does the condition under which a machine operates affect its reliability?

Reliability is affected by the conditions in which a machine operates. For example, a car is more reliable when driven on a smooth, paved road than when driven on rough terrain, as the operating conditions change.

How does time affect the reliability of a machine?

Time affects reliability because the longer a machine operates under certain conditions, the higher the chance it will fail. For instance, a car may be more reliable on rough terrain for 10 minutes than for 10 hours.

What would be a correct way to describe the reliability of a car?

A correct way to describe the reliability of a car would be to state its probability of not breaking down under specific conditions and a specified time interval, e.g., 'The car has a 75% reliability to run over rough terrain for 10 hours.'

Why is it important to specify the conditions and time when describing reliability?

It is important to specify the conditions and time because reliability can change depending on how long a machine operates and the environmental factors it faces. Both of these factors influence the machine's performance.

What is meant by 'reliability as a probability'?

Reliability as a probability means that reliability is always expressed as a percentage or a chance that a machine or system will not fail under the given conditions and time interval.

What will be covered in the next lecture after discussing the basic concepts of reliability?

In the next lecture, the focus will shift to the mathematical side of reliability, including how reliability is calculated.