VAS Documentation Manual

The Statistical Concepts, Theory and Computational Algorithms Forming the Foundation for the Variation Analysis System (VAS)

“A Heuristic Problem Formulation Methodology and Open Source Software System for the Analysis of Variation in Analytic Studies, Experimental Design Settings and Statistical Process Control Systems.”

Dr. Thomas A. Bishop and Mr. Chris Nicholas

Copyright © 2026 by Dr. Thomas A. Bishop and Chris Nicholas. All rights reserved.

Contents¶

Part I. Foundational Philosophy and Concepts

• 1.0 Introduction

Part II. The Scientific Philosophy Supporting the VAS Methodology

• 2.0 The Scientific Basis for Prediction in Analytic Studies

Part III. Cause Systems of Variation

• 3.0 The Concept of a Cause Systems of Variation

Part IV. The Structure of Cause Systems of Variation in Analytic Studies

• 4.0 Fundamental Concepts Associated with the Process

• 5.0 The Method of Rational Subgrouping

• 6.0 The Concepts of “Explainable”, “Unexplainable” and “Unexplained” Variation

• 7.0 The Structure of the Data Analyzed by VAS

• 8.0 The Statistical Structure for Rational Subgroups

• 9.0 The Sampling Plan and Sampling Design States

Part V. Statistical Theory Forming the Basis for the VAS Analyses

• 10.0 The VAS Statistical Models

Part VI. Shewhart Process Behavior Charts

• 11.0 The Xbar and S Charts

• 12.0 The Individual and Moving Range Charts

• 13.0 The Three Analytic Design States

Part VII. The VAS Analytic System

• 14.0 VAS Methods of Analysis

• 15.0 Taguchi Loss Function Analysis

• 16.0 Process Capability Analysis

• 17.0 The Test for ‘Maximum Information”

Part VIII. The Open Source Software System – “Process Behavior”

• 18.0 Process Behavior Software

Part IX. An Example of VAS Analyses

• 19.0 The Analysis of Cup Fill Weights

Part X. Application to Experimental Design and Statistical Process Control

• 20.0 Experimental Design Applications

• 21.0 Statistical Process Control Applications