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Find all articles across all article series listed in reverse chronological order.
With today’s software and problem solving methodologies, there is no reason to be teaching or using Taguchi methods. They have a range of limitations and assumptions, and better options exist and are easy to use. Watch this video to learn more! Avoid falling for the sales pitch for yesterdays tools. No reason to limit your options and your learning. [Read more…]
Leading reliability efforts is a hard road. The resource required to improve reliability is significant. The resource to demonstrate reliability is gargantuan.
Guest Post by Geary Sikich (first posted on CERM ® RISK INSIGHTS – reposted here with permission)
Good intentions do not make for the creation of a robust/resilient organization. Business Continuity plans, Disaster Recovery plans, Emergency Response plans, etc., that are standalone documents generally reflect good intentions – whether to meet regulatory requirements or to address governance. I would have to say that this should be a wake-up call for executives in all industries. We live in a complex and interdependent world. Complex systems are full of interdependencies that are hard to detect. The result is nonlinearity in responses to events, especially random events/shocks.
The odds of rare events are simply not computable. Model error swells when it comes to small probabilities. The rarer the event; the less tractable, and the less we know about how frequent its occurrence. [Read more…]
What readers will learn from this article.
This article introduces readers to heat transfer in heat exchangers. It explains the concepts of temperature gradients across walls and parallel- current and counter-current flows. Both shell-and-tube and plate heat exchanges are discussed along with their common operational problems and remedies.
Shell-and-tube and plate heat exchangers (HXCH’s) are recuperative type devices, meaning that flowing fluids exchange heat through a dividing wall. The exchange of heat occurs from the hotter liquid to the cooler one. The hotter liquid is at a higher energy level than the colder liquid and the energy flows from hot to cold in an attempt to reach a steady equilibrium state at an intermediate temperature. [Read more…]
Ponder this question: Let’s say you are an OEM and assemble parts made by various suppliers. When performing your Process FMEA, do you consider special characteristics for components in your Process FMEA? This question is discussed and answered in this edition of FMEA Q and A.
“The key to wisdom is this – constant and frequent questioning, for by doubting we are led to question, by questioning we arrive at the truth.”
Peter Abelard
Mercedes used to be known for their outstanding reliability. They were the benchmark for 80 years ,no exageration. The new CLA250 model which is their base model has a reliability that is 140% less than the average rated car. What??? [Read more…]
In the article Process Capability I – Overview and Indices, the main process performance indices were defined. In the article Process Capability Analysis II – Estimating Percent Defective, ways to calculate the percent defective were introduced.
Next, a way to estimate estimate the percent defective was discussed in Process Capability III – Cp vs Percent Defective. The data showed the process had a Cp ~0.46, so even if centered, a high percentage of parts would be non-conforming! In industry, it is common to see a Cp of about 1. The paradigm is that if the process range is just contained within the tolerance range, it is satisfactory. Such processes are marginally capable. A process mean shift away from the target or an increase in variation significantly increases the number of non-conforming parts. Process Capability needs to be increased. At a minimum, Cp should be greater than 1.33, but larger is better.
There are two approaches to improving process capability. One is to center the process and the other is to reduce variation. Both need to be accomplished.
Kishor forward the link to the recording to me and suggest it may of interest to the Accendo Reliability community. I agree. He does a great job discussing the topic and a clear and practical manner.
The video abstract is:
IEEE Life Fellow and Hudson Chair in the Department of Electrical and Computer Engineering at Duke University Prof. Kishor S. Trivedi visited Alibaba’s Hangzhou campus on Dec. 8th and talked about technical systems’ reliability and availability assurance methods based on probabilistic models. [Read more…]
I want my customers to be successful, every one of them. Yet there are times I can see the writing on the wall and I know as hard as I might try to show them a clear path to what it takes to be successful they have their own plan. Some of them are so complex that people become confused just trying to make sense of them, and others get so hung up in the minutiae of even the simplest of steps like listing a 3 part failure mode they will word-smith themselves to a point where folks just give up. I find myself asking “why do people have to make what is really so simple into something that appears to be complex?” [Read more…]
What is TRIZ and could it help you? We take a brief look and provide the basics of what it covers. Innovation is going to be key in the next several years as companies grow and emerge. [Read more…]
Guest Post by Jim Kline (first posted on CERM ® RISK INSIGHTS – reposted here with permission)
A predictable surprise is a risk event that in some form is known within the organization. It is of a nature that if left unresolved, it could be costly. But fixing the problem appears to have larger short run costs, than long term benefits. The Volkswagen diesel emissions fraud is one such example. It also a case where the penalties imposed outweighed the short term costs. Moreover, had a risk assessment occurred at several points along the way, there might not have been a scandal. [Read more…]
What readers will learn from this article.
Compressed air is one of the most used service fluids in industry. This article introduces the basic design concepts of an air compressor and discusses some of the common problems and solutions found in both reciprocating (piston goes up and down) and rotary screw (twin, meshed, rotating, helix) air compressors. [Read more…]
In my previous article, we established some high-level objectives for lean product development as follows:
Hi Ash,
Several managers at my company have told me they think I should pursue getting my Professional Engineer license. While I am not opposed to getting it, I am just not sure it will be worth it.
What do you think?
Thanks,
-Anonymous, Cincinnati, OH
This is part of a short series on the common distributions.
The Triangle distribution is univariate continuous distribution. This short article focuses on 4 formulas of the triangle distribution.
The distribution becomes a standard triangle distribution when a = 0, b = 1, thus it has a mean at the $- \sqrt{{c}/{2}\;} -$ and the median is at $- 1-\sqrt{{\left( 1-c \right)}/{2}\;}-$. The distribution becomes a symmetrical triangle distribution when $- c={\left( b-a \right)}/{2}\;-$.
The triangle distribution is used to approximate distributions when the actual distribution is unknown and bounded, often useful for Monte Carlo simulations. Other applications include subjective representation when there is evidence of bounds and a mode, or as a substitution to the beta distribution since it is bounded. [Read more…]