Lean Six Sigma - Control

Purpose of Control Phase

sustain improvements, monitoring & prevention, and ownership transition

Sustain Improvements

all gains achieved from DEAI are maintained and don’t regress performance

Monitoring & Prevention

continuous monitoring of process parameters, maintain standards, and prevent process drift through proactive management

Ownership Transition

transfer accountability to process owners who will lead long-term success and drive continuous improvement culture

What Happens Without Control?

risk of fading gains, lost investment, and rework multiplier

Control FMEA

tailored risk analysis, identify failure points, and prioritize & prevent

Tailored Risk Analysis

FMEA adapted for Control phase to identify vulnerabilities in new processes

Identify Failure Points

systematically examines where new process controls might break down, fail to detect issues, or become ineffective over time

Prioritize & Prevent

uses RPN to focus resources on highest-risk areas and design robust monitoring strategies

Control FMEA in Action

identify failure modes, evaluate risks (SOD), calculate RPN & prioritize, and develop control actions

What is a Control Plan

living document, operational details, and accountability link

Living Document

dynamic, regularly updated document that details how to monitor critical process inputs (Xs) and outputs (Ys)

Operational Details

specifies exactly what to measure, measurement, frequency, responsible parties, and specific response actions for out-of-control conditions

Accountability Link

directly connects to project goals and establishes clear process owner accountability for sustained performance

Key Elements of a Control Plan

process identification, critical variables, measurement systems, control limits, and response protocols

Process Identification

complete project details, process name, team members, and implementation date for traceability

Critical Variables

detailed list of process steps with identified CTQ characteristics and specifications

Measurement Systems

defined measurement methods, tools, sample sizes, and frequency for each critical parameter

Control Limits

statistical control limits, specification limits, and triggers for investigation or corrective action

Response Protocols

clear ownership assignments, communication channels, and documented reaction plans for deviations