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The Fear of Reliability

The Fear of Reliability

MTBF is a symptom of a bigger problem. It is possibly a lack of interest in reliability. Which I doubt is the case. Or it is a bit of fear of reliability.

Many shy away from the statistics involved. Some simply do not want to know the currently unknown. It could be the fear of potential bad news that the design isn’t reliable enough. Some do not care to know about problems that will require solving.

Whatever the source of the uneasiness, you may know one or more coworkers who would rather not deal with reliability in any direct manner.
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How to Create Performance Curves from the IMS

How to Create Performance Curves from the IMS

Guest Post by John Ayers (first posted on CERM ® RISK INSIGHTS – reposted here with permission)

Two schedule tools are widely used for the Integrated Master Schedule (IMS )around the world to manage projects. The first one is Microsoft Project (MS Project). The second one is Primavera P6.  They are both very good. Primavera P6 is an Oracle product originally designed for the construction industry. MS Project is simpler and easier to learn based on my experience. It also costs less than Primavera P6. DOD uses MS Project and typically requires it for use on government contracts. Other industries use one or the other depending on the size and complexity of the project.

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How Maintenance Contributes to Financial Performance

How Maintenance Contributes to Financial Performance

Industrial operations that use physical assets for production or service delivery need their assets to run optimally, and cause minimal operational disruptions when they don’t. Spending too little overall, or on doing the wrong things, always backfires. These short-term savings inevitably lead to breakdowns disrupting operations that cost much more in lost revenue than was saved by under-spending.

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Equipment Failure Prevention Needs Defect Elimination Strategy

Equipment Failure Prevention Needs Defect Elimination Strategy

To reduce maintenance costs and production downtime it is necessary to reduce the causes of the maintenance and downtime.  Both maintenance and downtime are an effect and not a cause.  The causes can be traced back to defects and errors from a variety of sources.  Knowing that defects eventually lead to future equipment failures, production downtime and lost profits, it is necessary put strategies into place to purposely prevent them occurring in the first place and to eliminate them if they are present.

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Systems/Validation Engineering (Part 2)

Systems/Validation Engineering (Part 2)

In Part 1 of this article series, we described validation engineering as the process of validating, monitoring and execution of product requirements to ensure customer needs are met.  The validation engineer is the validation process owner and works with subject matter experts to develop complete, accurate and testable requirements.

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Multiple-Failure-Mode Reliability Estimation

Multiple-Failure-Mode Reliability Estimation

“It is the policy of my Administration to respond to the coronavirus disease 2019 (COVID-19) pandemic through effective approaches guided by the best available science and data” [Biden Executive order, 2021]. That epidemic inspired the simultaneous nonparametric estimation of survival functions from case to recovery and case to death, without lifetime data (figure 1)!

Why not do the same for multiple-failure-mode data? This article shows nonparametric, multiple-failure-mode, maximum likelihood reliability estimation in a spreadsheet. Data are system first-failure times and the corresponding failure modes that caused the first system failures (table 1). However those data are dependent. I will explain the likelihood function, lnL, and how to find the maximum likelihood reliability estimates for all failure modes simultaneously.

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Hypothesis Testing Part-5: Chi-Square Test of One Variance

Hypothesis Testing Part-5: Chi-Square Test of One Variance

Dear friends, we are happy to released this fifth video in our series on Hypothesis Testing! In this video, Hemant Urdhwareshe explains the applicability of Chi-square test of one variance with an illustration! Hemant is Fellow of ASQ and is one of the few Certified Six Sigma Master Black Belts from ASQ having six certifications from ASQ.

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Gage R&R Analysis as a Tool for Understanding Measurement System Variation

Gage R&R Analysis as a Tool for Understanding Measurement System Variation

The term Measurement Systems Analysis refers to a collection of experimental and statistical methods designed to evaluate the error introduced by a measurement system and the resulting usefulness of that system for a particular application.

Measurement systems range from the simplest of gages like steel rulers to the most complex, multi-sensor measurement systems. Yet regardless of their sophistication, all gages are flawed and fail to deliver a perfectly accurate result to their users. This idea is best expressed by an equation fundamental to measurement science,

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Using Crow-AMSAA Plots in Disaster Predictions

Using Crow-AMSAA Plots in Disaster Predictions

Crow-AMSAA Analysis Overview

Crow-AMSAA Plots have a variety of names, such as Reliability Growth Plots or Duane Plots. The term “Crow” comes from Dr Larry H. Crow, who enhanced James T. Duane’s pioneering launch of this methodology, which was developed in the early 1960s (1). Crow successfully applied the method in the US Army Materials System Analysis Activity (AMSAA). The technique has blossomed into large amounts of new applications in industry such as but not limited to:

  • Making reliability more visible and manageable hence contributing to Reliability Improvement Programs,
  • Monitoring Design Optimization and Quality Performance,
  • Catastrophic or adverse event occurrence predictions and trends which in essence are the objective of this article.

In practical terms, The Crow-AMSAA technique involves plotting, most commonly, cumulative failures vs cumulative time on a log-log scale resulting in straight line plots (2). The line slope value (or Beta value) indicates improving, deteriorating, or constant failure occurrences. Due to the straight-line nature of the plots, future failure forecasts can be estimated. In plain words, based on the current trend, when is the next failure expected to occur? This method handles mixed failure modes, so it is, therefore, suitable for the complex nature of the generating units. [Read more…]

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Collaboration & Questions: Remember Facilitating Reliability is a Long Game

Collaboration & Questions: Remember Facilitating Reliability is a Long Game

Asking questions as a technical facilitator is a nuanced and deliberate process. All facilitators guide participants through solutions that are created, understood, and accepted by all. The “by all” part makes the role especially challenging and one that transcends a single session. Asking questions as a reliability facilitator contrasts with persuasion or manipulation, where narratives and emotions carry the day. The long game approach requires empathy, patience, consistency, and an in-depth understanding of context.

“Being a great facilitator requires commitment to your participants.”

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Being In The Flat Part of the Curve

Being In The Flat Part of the Curve

To me it means very little, as it rarely occurs. Products fail for a wide range of reasons and each failure follows it’s own path to failure.

As you may understand, some failures tend to occur early, some later. Some we call early life failures, out-of-box failures, etc. Some we deem end-of-life or wear-out failures. There are a few that are truly random in nature, just as a drop or accident causing an overstress fracture, for example. [Read more…]

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Examining Redundant Systems: Is RCM Necessary?

Examining Redundant Systems: Is RCM Necessary?

Welcome to another insightful video where we dive into the world of Reliability Centered Maintenance (RCM). I’m Nancy Regan, and today we’re tackling an important question: Do redundant systems require RCM?

Redundant systems, or protective devices, are vital because often they are our last line of defense when primary systems fail. But does this mean they need the same level of scrutiny as other systems?

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