The Bookshelf
The bookshelf serves as a repository for essays and case studies on the topics of Statistical Process Control (SPC), process behavior charts (control charts), and applied data analysis. The essays are organized according to the categories: Theory, Practice, and Supplier Quality.
Essays in the theory category discuss the theory that makes process behavior charts useful. They provide the reader with a governing framework for how to think about improvement in the vein of SPC. Essays in the Practice category put the theory to work.
They provide the reader with practical examples of the application of SPC. The essays in the Supplier Quality category are a specific subsection of practice as it relates to supplier quality.
The definition of quality: Clarity for modern manufacturing
Understanding the process capability indices: Terms, interpretation, & context
On writing, reports, & process behavior charts: A treatise on how PowerPoint makes us stupid
Network analysis: Advancing the utility of SPC
What the spec? The practical differences between process limits and specification limits
The importance of context
How to build an XmR chart
Poverty & Improvement
Characterizing inspection data
Using GD&T to improve an automated manufacturing process
Network analysis of supplier on-time delivery
Supplier Quality Ratios: A supplemental way to evaluate supplier quality
Same parts, new supplier: Evaluating supplier quality using process behavior charts
The datasets and Python code associated with each essay can be found here.
If you have questions regarding any of the essays or are interested in contributing to The Broken Quality Initiative send us an email at Qualityisbroken@gmail.com.
Theory
Quality has become an overused term of little substance. This essay elucidates how the current state of quality came to be and what we can do to fix it.
The process capability indices are a standard method by which process performance is graded. This essay explains these indexes and puts their use in context.
Modern manufacturing ecosystems produce data at a scale unrivaled in human history. Network analysis expands the utility of SPC to make sense of that data.
Modern business and industry has developed a detrimental relationship with PowerPoint. This essay explains how written reports can deliver us from this evil.
Practice
What is a spec limit? What is a process limit? This essay articulates operational definitions for process limits and spec limits and the context for the use of each.
Without context, data is random and miscellaneous. This essay articulates how process behavior charts establish context and imbue meaning.
Process behavior charts allow us to anticipate the future based on the past. This essay provides an example of how to achieve this using inspection data.
Process behavior charts are often seen as useful only in manufacturing. This essay is an example of how the utility of process behavior charts extends to other domains.
Calculating process limits and building XmR charts is a skill that is exceedingly. This essay teaches readers how to build XmRs on their own.
Engineering drawings are often viewed as immutable. This essay explores how questioning the drawing led to a larger number of assemblies being accepted.
Supplier Quality
On-Time Delivery (OTD) is a common supplier quality metric. This essay expands on the utility OTD using a novel SPC approach called network analysis.
Manufacturing in modern industry is often executed across global networks of suppliers. This essay outlines an alternative method for understanding supplier quality.
Same parts, new supplier, no problem! This essay serves as an example of how to evaluate existing parts made by a new supplier using process behavior charts.