# CRE Preparation Blog

A WordPress blog focused on aiding those preparing for the ASQ Certified Reliability Engineer exam. The following excepts are from the most recent blog entries. To see the full list of posts, please visit https://accendoreliability.com/creprep/, or click on one of the excepts below.

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- Creating a Dot Plot

Creating a Dot Plot Graphs contain information and often tell a story. Our interpretation of the graphic can be aided or hindered by the design or style of the plot. Cleveland and McGill (1984) studie … - Building and Using Pareto Charts

Building and Using Pareto Charts You may have heard of the 80/20 rule. The idea is that 80% of the wealth is held by 20% of the population. As an Italian economist, Vilfredo Pareto made this observati … - Beware of the Type III Error

Beware of the Type III Error There is a type of error when conducting statistical testing that is to work very hard to correctly answer the wrong question. This error occurs during the formation of th … - Sample Size for Hypothesis Testing of μ

Sample Size for Hypothesis Testing of μ A common question when setting up a hypothesis test is concerning sample size. An example, might be: How many samples do we need to measure to determine the new … - The Power of a Sample

The Power of a Sample We use a sample to estimate a parameter from a population. Sometimes the sample just doesn’t have the ability to discern a change when it actually occurs. In hypothesis testing, … - Type I and Type II Errors When Sampling a Population

Type I and Type II Errors When Sampling a Population In hypothesis testing, we set a null and alternative hypothesis. We are seeking evidence that the alternative hypothesis is true given the sample d … - Single Sample Z-test Hypothesis Testing for Mean with Known Variance

Single Sample Z-test Hypothesis Testing for Mean with Known Variance In the situation where you have a sample and would like to know if the population represented by the sample has a mean different th … - AND and OR Gate Probability Calculations

AND and OR Gate Probability Calculations In system modeling and fault tree analysis (FTA) we use a set of similar calculations based on Boolean logic, the AND and OR gate probability calculations. Wit … - The Risk Matrix as a Communication Tool

The Risk Matrix as a Communication Tool Not all risks the same. Some are minor with little consequence, while others are not. Every organization or reliability program facings a plethora of risks and … - There Might be 50 Reasons to Use a Histogram (or Bar Chart)

There Might be 50 Reasons to Use a Histogram (or Bar Chart) When confronted with a stack of data, do you think about creating a histogram, too? Just tallied the 50th measurement of a new process – jus … - Is a Professional Certification Worth It?

Is a Professional Certification Worth It? The way we learn, prove our worth, and the nature of work are all changing. Professional societies are struggling to adjust to these changes. Universities and … - Using a Strip Chart

Using a Strip Chart Sometimes we just need a simple plot of a few data points. When there is scant data a histogram or box plot just is not informative. This is a great use for a one dimensional scatt … - Building a Frequency Table

Building a Frequency Table In a meeting the other day, the presenter was talking about a range of different failures for the product in question. She talked about each issue, a bit about the failure a … - 5 Steps to Create a Measles Chart

Measles Chart Basics The clever Dr. John Snow mapped cholera cases during the epidemic of 1854 on a street map of the area. This type of mapping now called a measles chart, or defect location check sh … - Multi-voting: When More than One Vote is Better

Multi-voting: When More than One Vote is Better In brainstorming, you may face a large number of unique ideas even after affinity diagraming. Multi-voting is a great tool to gain consensus on the top … - Calculating the Probability of a Sample Containing Bad Parts

Calculating the Probability of a Sample Containing Bad Parts Received a question from a reader this morning that will make a nice tutorial. A box contains 27 black and 3 red balls. A random sample of … - An Introduction to the Cause and Effect Diagram

An Introduction to the Cause and Effect Diagram Also called the Ishikawa or fishbone diagram, the cause and effect diagram is a graphical tool that enables a team to identify, categorize, and examine … - Mind Mapping for Non-Linear Thinking

Mind Mapping for Non-Linear Thinking Sometimes a process doesn’t happen one step at a time. Sometimes, a problem we’re trying to solve has many moving and interacting elements. Mind Mapping is a techn … - Check Sheet: Capture Data Quickly

Check Sheet: Capture Data Quickly There are two common uses for a check sheet. First, to summarize historical data, or second, to collect observations. A byproduct of creating a check sheet is team ag … - MSA 2 – Gage Variation

Introduction Most of us rely on accurate measurements. If these measurements are unreliable, then our decisions could be based on false information. How can we have confidence in our measurements? The …

## Course offerings

If you or your team would like a custom CRE prep course, just let me know and we’ll make arrangements to make it happen. I also teach a live 32 hour CRE Preparation course through the

ASQ Silicon Valley Section when we have at least four students. The course runs for the 8 weeks prior to semi annual exam. Learn more about the CRE at the ASQ site.