How do you select the appropriate sampling plan and measurement methods for PPAP dimensional reports?

2 Measurement methods

Measurement methods are the tools and techniques used to measure the dimensions and features of a part. They should be accurate, precise, and repeatable, matching customer specifications and tolerances. Additionally, you should consider the cost, time, availability, training, and calibration requirements. Manual methods involve hand tools such as calipers, micrometers, gauges, and rulers; they are simple and flexible but require more skill, time, and potential for human error. Semi-automated methods use machines or devices that assist the operator in measuring the part; they are faster, more accurate, and more consistent than manual methods but require more investment and maintenance. Automated methods use machines or devices that measure the part without human intervention; they are the fastest, most accurate, and most reliable measurement methods but also the most expensive, complex, and specialized.

3 Dimensional report template

A dimensional report template is a document that summarizes the results of the measurement methods and compares them with the customer's specifications and tolerances. This should include the part name, number, revision, and description; customer and supplier contact information; sampling plan details; measurement method details; dimensional characteristics; measurement results; and remarks and comments. You can use a standard dimensional report template or create your own based on your customer's requirements. It's important to make sure that the template is clear, consistent, and complete, and that it meets PPAP documentation guidelines.

4 Measurement system analysis

Measurement system analysis (MSA) is a process of evaluating the accuracy and precision of your measurement methods and identifying any sources of variation or error that may affect your results. This helps ensure that your measurement methods are capable of detecting any significant differences between the parts and the specifications. To assess this, MSA involves conducting studies such as gage repeatability and reproducibility, bias, linearity, and stability. Before submitting your PPAP dimensional report, it's important to perform MSA and document the results and actions taken to improve your measurement system.

5 Continuous improvement

Continuous improvement is a principle of quality management that seeks to achieve excellence and customer satisfaction through constantly monitoring, evaluating, and optimizing processes and products. This includes sampling plans and measurement methods as well. To support these efforts, control charts, capability analysis, and root cause analysis can be used. Control charts graph the measurement results over time and show the upper and lower control limits and the process average. Capability analysis compares the variation of your measurement results with the part's specifications and tolerances. Root cause analysis identifies the underlying causes of any defects or errors in your measurement system. You should conduct continuous improvement activities regularly and communicate your results and actions to your customer and stakeholders.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?