Sustaining Gains: Statistical Process Control
Introduction to the Control phase
Many Six Sigma belts and teams do a good job in the analyze and improve phase. However, the improvements do not sustain over a long period as certain important requirements of the control phase are not met. Typical causes of the failure to sustain improvements are as follows:
- Inadequate training to operators on the changed process or equipment
- Validation of improvement for a short period of time and/or small sample sizes
- Inadequate control plan and/or audits
- Controls are dependent on people's compliance with the stated precautionary measures
- Process improvements may be articulated or specially ‘managed’ only to demonstrate to the sponsor or management that the ...