What are the key elements of a control plan and how do you monitor and update it in APQP?

1 Control plan elements

A control plan typically consists of six sections: header, product and process characteristics, process control methods, reaction plan, measurement system analysis, and part and process approval. The header provides basic information about the product, process, supplier, customer, and revision history. The product and process characteristics section identifies the critical or special characteristics that affect the quality, safety, or performance of the product or process, and specifies the target values, tolerances, and evaluation methods. The process control methods section describes the tools, techniques, and procedures to monitor and control the product and process characteristics, such as control charts, checklists, inspection plans, and sampling methods. The reaction plan section defines the actions to be taken in case of nonconformities, deviations, or out-of-control situations, such as containment, correction, root cause analysis, and corrective actions. The measurement system analysis section evaluates the accuracy, precision, and repeatability of the measurement systems used to assess the product and process characteristics, such as gauge repeatability and reproducibility (GRR) studies, calibration, and verification. The part and process approval section verifies that the product and process meet the customer specifications and requirements, such as production part approval process (PPAP), first article inspection (FAI), or run at rate.

2 Control plan monitoring

The control plan is not a static document, but a dynamic one that requires regular monitoring and updating to reflect the current state of the product and process. The control plan monitoring involves collecting and analyzing data from the process control methods, measuring the performance indicators, identifying and resolving issues, and implementing improvements. The control plan monitoring can be done at different frequencies and levels, depending on the complexity, risk, and maturity of the product and process. Some examples of control plan monitoring activities are daily production checks, weekly quality reviews, monthly audits, quarterly reports, and annual reviews.

3 Control plan updating

The control plan updating involves revising and modifying the control plan elements based on the results of the control plan monitoring, the feedback from the customer, the changes in the product or process design, or the new requirements or standards. The control plan updating can be triggered by various events, such as process capability improvement, defect reduction, customer complaint, design change, supplier change, or regulation change. The control plan updating follows a systematic process that includes reviewing the current control plan, identifying the gaps or opportunities for improvement, proposing and evaluating the changes, implementing and verifying the changes, and communicating and documenting the changes. The control plan updating should also involve the relevant stakeholders, such as the customer, the supplier, the engineering team, the production team, and the quality team.