This is the first annual survey to find what you recommend for those preparing for the ASQ CRE exam.
See the full list of reliability references for the CRE exam, for reliability and maintenance engineers at Accendo Reliability. [Read more…]
Product Reliability Design Guidelines
Product Reliability Design
One way to capture and disseminate reliability engineering related information and advice is through internal documents. This of course only works if they are both useful and used.
Focus on gathering and providing essential and meaningful information that will improve the reliability of your product. Another element that makes these design guidelines valuable is if they save time. Engineers love to save time. [Read more…]
Software Defect Phase Containment
Software Defect Phase Containment
The software element of products continues to grow.
Likewise, the number of field failures due to software issues continues to grow. Writing code is relatively straight forward, and some may even say it’s fun.
The process of debugging, or finding and fixing software defects, is not fun. [Read more…]
For Maximum Test Value, Take it to the Limit!
When we go to an automobile race such as the Indianapolis 500, watching those cars circle the track can get fairly boring. What is secretly unspoken is that everyone observing the race is watching for a race car to find and sometimes exceed a limit, finding a discontinuity. The limit could be how fast he enters a curve before the acceleration forces exceed the tires coefficient of friction, or how close to the racetrack wall, he can be before he contacts it and spins out of control. Using the race analogy, [Read more…]
Approaches to Assess Customer Reliability Needs
Approaches to Assess Customer Reliability Needs
Just asking a customer how reliable they want your product often provokes an honest answer. The customer, and you most likely, do not want any failures.
Failures are troublesome or in some cases dangerous.
You and your customers realize that not every unit produced will operate over a long and useful life. There is some chance that something will fail. The definition of ‘some’ is often vague. [Read more…]
Reliability Role in Safety and Liability
Reliability Role in Safety and Liability
The reliability engineer may have many roles within an organization.
You may be specialized and focused only on the analysis of field data. Or you may be a member of the organization’s strategic leadership team.
You might support one or more product development teams, or work with a team of reliability professionals supporting just one subsystem. [Read more…]
Reliability Modeling using Monte Carlo
Modeling Complex Systems and Their Variability
Monte Carlo relies on data that describes the variation of elements within the system. It also connects the elements such that they result is an estimate of performance.
For reliability modeling, this is easiest to imagine for a series system.
For a system with two elements in series, a very simple reliability block diagram multiples the expected reliability for each block to determine the system reliability value. Yet, it is possible to have both elements at the low end of the range of possible reliability values, or the high end or a mix.
That is the value of the Monte Carlo approach. [Read more…]
Why the Drain in the Bathtub Curve Matters
Most reliability engineers are familiar with the life cycle bathtub curve, the shape of the hazard rate or risks of failure of a electronic product over time. A typical electronic’s life cycle bathtub curve is shown in figure 1. [Read more…]
Ethics and Your Work as a Reliability Engineer
Ethics relate to the moral correctness of a person’s behavior given the groups moral principles.
Society, in general, has a set of standard expectations to guide our behavior. This includes fundamentals such as not harming others or behaving in a deceitful manner.
Religious, professional and informal ‘codes’ document the set or principles which guide our behavior in line with moral correctness. [Read more…]
A Brief Introduction to Fault Tree Analysis
Fault Tree Analysis (FTA) is a technique to explore the many potential or actual causes of product or system failure.
Best applied when there are many possible ways something may fail. For example, when my car doesn’t start, it could be a dead battery, faulty started, loose wire, no fuel, and on and on. [Read more…]
2 Versions of Product Life Cycle Phases
Each organization creates their own version of a product life cycle.
Often there are phase gate reviews that signal a transition from one phase to the next. In general, each set of phases follows a common progression from idea to retirement.
There are many references that include a description of the life cycle phases, so let’s explore two of them. [Read more…]
Field Data and Reliability
Customers experience product failures.
Understanding these failures that occur in the hands of customers is an essential undertaking. We need this information to identify increasing failure rates, component batch or assembly errors, or design mistakes. [Read more…]
No Evidence of Correlation: Field failures and Traditional Reliability Engineering
Historically Reliability Engineering of Electronics has been dominated by the belief that 1) The life or percentage of complex hardware failures that occurs over time can be estimated, predicted, or modeled and 2) Reliability of electronic systems can be calculated or estimated through statistical and probabilistic methods to improve hardware reliability. The amazing thing about this is that during the many decades that reliabilityengineers have been taught this and believe that this is true, there is little if any empirical field data from the vast majority of verified failures that shows any correlation with calculated predictions of failure rates.
[Read more…]
Success Testing Formula Derivation
The planning of environmental or reliability testing becomes a question of sample size at some point.
It’s probably the most common question I hear as a reliability engineer – how many samples do we need. [Read more…]
How Safe is Safe Enough for Your System?
Estimating the set of stress and stress curves is an interesting exercise that may have a greater purpose: safety.
The connection is clear when considering the potential consequences of failure.
For example, the loss of braking power when landing an aircraft may result in the aircraft rolling off the end of the runway. This could be into a river or road and may have a rather poor outcome not only for the aircraft. [Read more…]
