Control Plan

What is a Control Plan?

A control plan is a comprehensive document that outlines the strategies and actions required to maintain the improvements made in the process. Thus, it serves as a roadmap for sustaining the gains achieved during the previous phases of the project. Additionally, the plan ensures that the process remains in control, meets the desired performance levels, and continues to deliver high-quality outputs.

Control Plan

Importance of Control Plan:

  1. Sustaining Improvements:

    The control plan helps to lock in the improvements made during the Improve phase and ensures they are maintained over time. Therefore, this prevents the process from reverting to its previous state.

  2. Predictability and Stability:

    A well-executed control plan enhances process predictability and stability, reducing variations and minimizing defects or errors in the outputs.

  3. Continuous Monitoring:

    The control plan establishes a system for ongoing monitoring and measurement of key process indicators. This eventually enables quick identification of potential issues and the implementation of corrective actions before they become major problems.

  4. Response Mechanisms:

    In the event of any deviation or nonconformity, the control plan defines the appropriate response mechanisms and action plans to bring the process back into control.

  5. Standardization:

    By documenting the standardized procedures and methods, the control plan ensures that all team members are aligned and follow the same processes consistently.

Components of a Control Plan:

  1. Process and Output Metrics:

    Clearly define the critical process metrics and output measures that need to be monitored. These can be quantitative or qualitative and should align with the project objectives.

  2. Control Limits and Targets:

    Set appropriate control limits for each metric. Control limits are used to determine if the process is in control or if there are any signs of instability. Targets are the desired performance levels for the metrics.

  3. Sampling and Data Collection Frequency:

    Specify the frequency at which data will be collected and the sampling method to ensure that data is representative of the process performance.

  4. Responsibility and Ownership:

    Clearly assign responsibilities for data collection, monitoring, and responding to any out-of-control situations. Define who will be responsible for the overall execution of the Control plan.

  5. Response Plans:

    Outline the actions that need to be taken when the process goes out of control or when performance metrics deviate from the established limits.

  6. Communication Plan:

    Detail the communication strategy for reporting performance results and any significant changes to stakeholders.

  7. Training and Documentation:

    Identify any additional training needs for team members and ensure that all the procedures are thoroughly documented for reference.

Remember, the Control plan is not a static document. It should be regularly reviewed and updated as the process evolves, and new insights are gained. By following the Control plan diligently, we can ensure the long-term success of the improvements and maximize the benefits of the project.


Component Description
Process and Output Metrics - Defect Rate: Number of defects per unit of output
- Cycle Time: Time taken to complete one cycle of the process
- Customer Satisfaction Score: Measured through surveys or feedback
Control Limits and Targets - Defect Rate: Upper Control Limit (UCL) = 2 defects per unit
- Defect Rate: Lower Control Limit (LCL) = 0 defects per unit
- Cycle Time: Target = 4 hours
- Customer Satisfaction: Target = 90%
Sampling and Data Collection Frequency - Defect Rate: Random sampling daily from production output
- Cycle Time: Continuous monitoring of process time
- Customer Satisfaction: Quarterly surveys
Responsibility and Ownership - Defect Rate: Production team leader
- Cycle Time: Process engineer
- Customer Satisfaction: Quality assurance manager
Response Plans - Defect Rate out of control (above UCL or below LCL): Stop production, conduct root cause analysis, implement corrective actions
- Cycle Time exceeding target: Analyze process steps, identify bottlenecks, optimize workflow
- Customer Satisfaction below target: Investigate reasons, address customer concerns, improve service delivery
Communication Plan - Weekly performance reports to production and management teams
- Monthly updates to all stakeholders on process performance and improvements
Training and Documentation - Conduct training sessions on data collection methods and analysis techniques for team members
- Document all process procedures and updates in a centralized knowledge base


By implementing and following this control plan, the company can ensure that the improved assembly process is maintained, defects are minimized, and the product quality meets the desired standards. Regular monitoring, control measures, and clear responsibilities help sustain the improvements achieved during the DMAIC project.

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