Measuring Supply Chain Forecast Accuracy

Measuring Supply Chain Forecast Accuracy is usually done with Mean Absolute Percent Error or MAPE, the average of percentage errors. But there are several other metrics to consider. Here’s an […]


Here’s a more modern z Score Calculator And another table

Lean Six Sigma Certification Game

A friend and colleague, Bill Bentley, writes about the use of professional certifications in the recruiting industry. I had a long talk with a senior IT professional in Chicago last […]

Forget the 80/20 Rule

In the late 1800s, economist and avid gardener Vilfredo Pareto established that 80% of the land in Italy was owned by 20% of the population. While gardening he later observed […]

EVOP – Evolutionary Operations

Evolutionary Operations, first described by George E. P. Box and Norman R. Draper in in their book Evolutionary Operation – A statistical method for process improvement, New York: John Wiley […]

Process Improvement in a Down Economy

Many business leaders fail to see the opportunities that an economic downturn provides.  To take advantage of opportunities you first need to make a rapid assessment of your vulnerabilities and […]


Johann Carl Friedrich Gauss (1777-1855)  seen here on a German 10 Deutsche Mark banknote was a mathematician, astronomer, scientist noted for least squares, the normal distribution, and number theory.  Also […]

5 Rules of On-error Training

1. Ownership Rule – the person who first detects the problem is responsible for finding the root cause of the problem. 2. Quickly Rule – the problem must be dealt […]

PowerPoint and other miscommunications

Recently read Edward R. Tufte’s The Cognitive Style of PowerPoint: Pitching Out Corrupts Within and initially dismissed his thesis as troglodyte.  Now sensitized, I’ve been watching for evidence of PowerPoint […]

Safety Stock Calculations

When I first learned inventory planning the math was rather simple.  On top of the cycle stock (expected demand during lead time) I would add a percentage or a number […]

Minitab training from Value-Train

Minitab is possibly the most widely used statistical software package in the Six Sigma world. Our friend Bill Bentley has just announced online training through Value-Train. This is a great […]