Guest post by John Hunter, founder of CuriousCat.com.
This webcast shows Brian Hwarng’s presentation, The Funnel Experiment, at the 2015 Deming Research Seminar. As Brian says:
The purpose [of the funnel experiment] is to demonstrate, by theory, the losses that are caused by tampering.
Chapter 9 (“The Funnel”) of The New Economics is a good source to learn more about the funnel experiment.
Brian discusses the impact of interactions on results. The funnel experiment illustrates that the impact of results are dependent on other factors. This insight is critical to understanding Deming’s ideas and applying them.
Organizations are complex systems with many interdependent parts. When making decisions it is important to not just have data but to understand how that data reflects an interaction of many factors to create a specific result. Over-simplification is often one of the problems in most organizations. Seeing results as the responsibility of the person close to the result is a symptom of such thinking. Even as system as simple as the funnel experiment shows that interactions are a natural part of any system. Dr. Deming knew this and made appreciation for a system an integral part of his management system.
When people react to individual results (when those results are merely the expression of the natural variation within the system) the problems and variation related to that process increase. Instead organizations need to develop systems to measure process results over time and use the PDSA cycle to experiment and learn how to improve the capabilities of the process in order to continually improve the results.
Read Dr. Hwarng’s paper: Insights and Innovations via the Expanded Funnel Experiment.
View the slides for the Dr. Hwarng’s funnel experiment presentation.
Related: We Need to Understand Variation to Manage Effectively – Knowledge of Variation