Your Reliability Engineering Professional Development Site
When designing equipment and processes, engineers leave a safety margin that ensures equipment remains functional when a fault or defect is affecting it partially or wholly. Minor defects affecting production assets should not cause immediate breakdowns. A fault-tolerant system remains operational for predetermined intervals before undertaking corrective measures. Faults affecting the operation of different systems emanate from more than a single source. [Read more…]
“If no one ever took risks, Michelangelo would have painted the Sistine floor.” – Neil Simon
FMEA and Risk Management are two distinct bodies of knowledge. This article explores some of the interactions between these two important methods. It is not intended to be a complete analysis of the similarities, differences, and linkages between FMEA and risk management. Rather, it is a high-level overview.
At first glance, a computerized maintenance management system (CMMS) and Failure Modes And Effects Analysis (FMEA) may appear to be worlds apart. But take a deeper dive, and it’s easy to see that they both share a common component: data. The core of any CMMS is defined by gigabytes of data that guarantee its usefulness and functionality, while the success of the systematic steps in FMEA depends on good quality data.
Many companies miss out on the value of System FMEA and begin with lower level sub-assemblies or components. This article explains why it is usually best to begin with a properly done System FMEA.
“Big whirls have little whirls,
That feed on their velocity;
And little whirls have lesser whirls,
And so on to viscosity.”
Lewis Fry Richardson
“Prediction is very difficult, especially if it’s about the future.” Niels Bohr
In an FMEA, is it possible to think of everything that might happen in the future? What strategies can be used by FMEA teams to maximize the opportunity to anticipate what can go wrong, so risk can be reduced to an acceptable level?
Equipment failure is a reality that cuts across every industry. And when it occurs, its impact can vary from minimal inconveniences with localized damages that are easily contained and repaired, to significant incidents with damaging effects on the environment accompanied by several health and safety implications.
DFMEA’s definitely have a bad reputation as exercises that consume an enormous amount of time and unfortunately yield little value to the program.
And can be miserable to experience.
A quote from a customer “We aren’t going to do any more DFMEA’s because we feel a bit traumatized by the last round.”
I have also seen DFMEA’s be a cornerstone to a design program using its resources with surgical precision to improve the product.
I started to think about the differences between the ineffective and effective DFMEA’s. Here are some of the steps that I believe make the “good ones” GOOD. [Read more…]
Products and equipment start with a design. The functions and performance occur or do not occur according to the capabilities designed into the system.
I learned early in my career, as a manufacturing engineer, that some products were much easier to manufacture (less yield loss) than others, and it was often the design of the product that made the difference. [Read more…]
It is rare that a third party generated FMEA/FMECA has any value. The development or manufacturing teams and supporting staff should comprise the bulk of the study’s team. Team size for a specific study would include 4 to 10 individuals.
The FMEA/FMECA should provide clear action items that may include:
Conduct research or experiments to understand and quantify uncertainty. This may include exploring how an item responds to specific stress, errors or inputs. Or include experiments to estimate the occurrence rating for a specific potential cause of a failure mode. [Read more…]
Failure modes and effect analysis is a tool to identify potential failures and prioritize based on severity, occurrence, and detection. I like to describe FMEA as an organized brainstorm. You probably have some experience with FMEA.
In some industries, there is a high expectation or mandate to do an FMEA study. In some industries FMEA maybe just another tool to consider using during various stages of the product or asset lifecycle.
In my opinion, FMEA should be a part of your project plan when it is likely to add value.
Value in the sense that the organization will receive an adequate benefit based on the investment to conduct the FMEA study. [Read more…]
Failure modes and effect analysis (FMEA) is a tool that works to prevent process and product problems before they occur.
I like to define FMEA’s as an organized brainstorm. The process examines a product or process and asks what could go wrong. Then the team systematically determines and rank orders for each failure mode:
– the severity of the problem when it occurs
– the probability of the problem occurring
– the ability to detect the problem before it occurs
Good design engineers think about how the design could fail and improve the design. FMEA provides a structured team approach to further improve the design.
Fred i was asked this question and wanted to know what your thoughts were on this. R and D asked me what was the criteria to decide if to test at a component level or at a system level , my answer was that it should depend on what is the reliability and confidence level of the component
your thoughts? [Read more…]