Business Process Improvement What is the plus 4 method? March 15, 2026 by Mercier | Leave a Comment The Plus 4 Method is a technique used in statistical process control (SPC) to identify and analyze sources of variation in a manufacturing or business process. It helps teams pinpoint the four key areas that most influence a process’s outcome, enabling targeted improvements for greater efficiency and quality. Understanding the Plus 4 Method: A Deep […] Read more ยป