Issues in Data Collection

There are a number of issues that we must consider when collecting and using data for analysis purposes.  One of those issues is the Hawthorne Effect, also referred to as the observer effect.   This is a phenomenon where individuals change their behavior because they know they are being observed or watched.    The term was coined […] read more

On December 8th, 2014, posted in: Six Sigma by Tags: ,

Discrete and Continuous Data

A clear understanding of the difference between discrete and continuous data is critical to the success of any Six Sigma practitioner.  The decision about which statistical test is appropriate under a specific set of circumstances very often depends on whether the underlying data is discrete or continuous. Discrete data are also referred to as attribute […] read more

The Cost of Quality

Six Sigma is perceived by many as an approach to quality improvement.  In fact, quality improvement is a means to two important ends.  One is improved customer satisfaction, and the other is saving money. The marketplace determines to a great extent how much a company can charge for goods and services.   The company determines how […] read more

On August 8th, 2014, posted in: Six Sigma by Tags: ,

Measuring Process Performance – Average and Variation

Process performance is universally described in practice by collecting data and calculating the mean (i.e. the mathematical average) performance.  Unfortunately, the variation around the mean is almost never included when describing process performance.  This is a critical oversight that is addressed by the Six Sigma methodology. Let me illustrate with an example that I often […] read more

On May 25th, 2014, posted in: Six Sigma by Tags: , , ,