A longer video from Nancy with an introduction to the reliability centered maintenance, proactive maintenance, plus the anatomy of a well-planned RCM program.
[Read more…]How to Succeed at RCM (Part 3): Successful Planning
Articles
Find all articles across all article series listed in reverse chronological order.
Histogram and Descriptive Statistics on Excel
Dear friends, some of the participants in our training programs requested me to make a video on how to use Excel to plot histograms and descriptive statistics using Analysis ToolPak. This video illustrates how to do this for a sample data of admit time of patients in a hospital. Hope you find this useful.
[Read more…]Calculating when to Economically replace Assets
Optimum replacement time – Theory
The optimal asset replacement time calculation has one goal, and that is to calculate the lifetime of when assets should be operational as to have the lowest possible operating cost over its lifetime.
This means balancing two opposing forces, namely the increasing operational cost and unreliability of the asset as it ages, with the decreasing effective cost of ownership. [Read more…]
Time to Event Analysis: An Introduction
Introduction
I am currently reading the book Survival Analysis: Techniques for Censored and Truncated Data, Second Edition (John P. Klein and Melvin L. Moescheberger). Although the techniques presented in this book focus on applications in biology and medicine, the same statistical tools can also be applied to disciplines ranging from engineering to economics and demography. I have a background in mechanical engineering and am interested in applying survival modeling concepts to data from reliability engineering, manufacturing and quality assurance. This article is the first of, hopefully, many articles that I intend to write as I finish reading different chapters from the book.
The data set(s) that will be analysed are the ones that have been used as examples in another book: Statistical Methods for Reliability Data, Second Edition (William Q. Meeker, Luis A. Escobar, Francis G. Pascual). Both the books I mentioned are excellent resources for anyone who is interested in learning more about this topic.
In this article, we will analyze vehicle shock absorber failure time data Failure time data is also known as survival data, life data, event-time data or reliability data, depending on the field of study. and estimate a few basic survival quantities. The data contains failure times (in kilometers driven) and the mode of failure, first reported by O’Connor (1985) O’Connor, P. D. T. (1985). Practical Reliability Engineering. Wiley. [54, 610]. We will ignore the mode of failure for now and will only consider whether a failure occurred or not, i.e., censored. In a future article, I plan to use the different failure modes to discuss competing risks for time-to-failure data.
Hypotheses Testing – What is That?
Well, this article will be a little bit challenging and full of statistical terms. I would categorize the “Hypothesis testing” as most of common use in statistical analysis.
First time of usage happened in 1700s, but actual popularisation at early 20th century:
[Read more…]Lifetime Evaluation v Measurement
Lifetime: Evaluation vs. Measurement
Guest Post by Oleg Ivanov
How can we tell whether an iron is hot enough? The answer is obvious: We can measure temperature by using a thermocouple and a meter. But, in practice, we lick our finger and touch the iron. Sizzle…. Yes, it’s hot!
We know a priori the boiling temperature of water and we can evaluate the temperature of the iron. This method has a lower cost. [Read more…]
15 Ways to Safely Reduce the Size of Your Maintenance Crew!
Discover 15 ways to operate so there is less maintenance, fewer maintenance people, lower maintenance costs and (because there is less maintenance) your plant runs reliably for longer! Most of the 15 topics covered are new to operations and maintenance. Each one reduces downtime, save money and improves operating uptime and performance.
Project Assurances
Guest Post by Malcolm Peart (first posted on CERM ® RISK INSIGHTS – reposted here with permission)
We have many kinds of assurance in the project management world. These, generically include business assurance to track the economic viability of a project, technical assurance for the technical integrity of a product, process or system, and user assurance to check that specified requirements have been met. Assurance demonstrates compliance to a project’s business case, meeting end user’s operational requirements, and that there is technical compliance against codes, standards or specifications.
[Read more…]Pareto Chart on Excel
Weekly Scheduling
George Williams, Founder and CEO of ReliabilityX, discusses how Weekly Scheduling helps drive improvement in the efficiency of the maintenance organization! Have any questions? Drop a comment below!
[Read more…]Three Ways Great Facilitators Anticipate Trouble
Great facilitators anticipate trouble when guiding groups. We normally consider conflict between the participants as the most likely disruptor. However, facilitators should be prepared to overcome a handful of disruptor types in collaborative sessions. This article discusses technology misfires and provides three case examples with solutions.
Virtual Meetings Get Zoom-Bombed
We’ve been having monthly Pee Dee River Basin Council meetings for nearly two years. I serve as the facilitator of the 25-person group and Clemson’s University’s Tom Walker is the logistics coordinator. The meetings are in a hybrid format that allows the public and stakeholders to view the meetings virtually. The meeting was Zoom-bombed mid-way through the January 2024 meeting.
[Read more…]Futility of Using MTBF to Design an ALT
Futility of Using MTBF to Design an ALT
Let’s say we want to characterize the reliability performance of a vendor’s device. We’re considering including the device within our system, if and only if, it will survive 5 years reasonably well.
The vendor’s data sheet lists an MTBF value of 200,000 hours. A call to the vendor and search of their site doesn’t reveal any additional reliability information. MTBF is all we have.
We don’t trust it. Which is wise.
Now we want to run an ALT to estimate a time to failure distribution for the device. The intent is to use an acceleration model to accelerate the testing and a time to failure model to adjust to our various expected use conditions.
Given the device, a small interface module with a few buttons, electronics, a display and enclosure, and the data sheet with MTBF, how can we design a meaningful ALT? [Read more…]
Test Design for Component Life
Understanding FMEA Compensating Provisions
Risk is a function of how poorly a strategy will perform if the “wrong” scenario occurs. Michael Porter
The use of Compensating Provisions in FMEA is a key part of many FMEA standards. Regardless of what FMEA standard you are using, everyone who aspires to doing FMEAs properly should understand the role of mitigating the risk of very high severity.
Effective Safety Communications
Guest Post by Bill Pomfret (first posted on CERM ® RISK INSIGHTS – reposted here with permission)
Recently, I was talking to the Managing Director of a large recruiting firm for safety professionals in Toronto about the importance of communication skills.
It was very clear that safety leaders are just expected to be experts in the technical aspects of safety, but it’s the ability to communicate about safety that sets apart the great safety leaders from the mediocre.
[Read more…]