IntermediateTopic 42 of 102Manufacturing, Robotics & Systems
Reliability engineering
Predict and improve probability of failure-free operation.
In depth
Reliability R(t)=e^{-λt} for constant failure rate; bathtub curve (infant mortality, useful life, wear-out); series systems multiply reliabilities, parallel (redundant) systems 1-Π(1-R_i). Tools: life testing, accelerated tests (Arrhenius), Weibull analysis, MTBF prediction, derating and redundancy.
Key points
- FIT rates
- Burn-in
- Design margins
ExampleA 100 000 h MTBF device has 0.9% chance of failure in 1000 h.
Reliability describes how long equipment works without failure, which is central to safety, warranty costs and customer confidence.
What is Reliability engineering?
Predict and improve probability of failure-free operation.
Why is it important to understand reliability engineering?
Reliability describes how long equipment works without failure, which is central to safety, warranty costs and customer confidence.
What is mean time between failures?
The average operating time between failures of a repairable system, which is used as a reliability measure.
What is the bathtub curve used for?
It shows early failures, a steady failure rate and wear-out failures over life, which guides testing, maintenance and warranty decisions.
How is Reliability engineering used in practice?
Typical applications include estimating the mean time between failures of a pump, comparing two motor designs for expected life in service and setting a warranty period based on predicted failure rates.
What should I learn before Reliability engineering?
Study "Maintenance engineering" first (topic 41 of 102 in Manufacturing, Robotics & Systems). It covers the groundwork this topic builds on.
What are the key points of Reliability engineering?
FIT rates. Burn-in. Design margins.
Can you give an example of Reliability engineering?
A 100 000 h MTBF device has 0.9% chance of failure in 1000 h.
What comes after Reliability engineering?
The next topic is "Failure modes and effects analysis", which builds directly on this one.
How difficult is Reliability engineering?
It is classed as Intermediate in Manufacturing, Robotics & Systems (topic 42 of 102). It is an intermediate topic. Work through the beginner topics in Manufacturing, Robotics & Systems first.