A short time ago we covered DOE 101, the basics of Design of Experiments in an Insider Series Webinar You can watch this webinar here. DOE 201 is a follow on Insider Series Webinar on advanced DOE techniques, mostly what are called screening and reduced designs. Screening designs are performed when there are so many factors to analyze that performing a DOE with all of the factors at a high number of factor levels is not practical. As an example, suppose there is a DOE with 6 factors, each at 4 levels. This DOE would require at least 4⁶ = 4096 runs. 

In cases like this one, screening experiments are often performed to determine which factors are important. In a screening experiment, each factor is only evaluated at two levels. So in this case the number of data points, or runs, required is only 2⁶ = 64. In some cases, it is possible to reduce the number of runs further by employing a fractional factorial design.

This webinar will discuss how to perform these screening and fractional factorial DOEs and the risks in doing so. In the webinar, several screening and fractional factorial DOEs will be analyzed with Minitab. The data will be given to the attendees so that they can practice on their own. A 30 day trial version of Minitab is available for free. 

This Insider Series Webinar will cover statistical process control (SPC). SPC is an important tool in controlling SMT assembly processes, especially stencil printing. 

The webinar will start with a discussion of the 6 Ms of variation and then delineate common cause and special cause variation. The difference between precision and accuracy will then be clarified. After discussing the precision tolerance ratio, the technique to perform a Gage R&R (Repeatability and Reproducibility) analysis will be presented. Process control charts, and their development by Walter Shewhart, will then be discussed including the Shewhart Rules. Several sets of SPC Xbar-R and C Chart data will then be plotted and analyzed with Minitab®. A 30 day trial version of Minitab is available for free.

The webinar will conclude with a discussion and application of the process capability indices C_p and C_px. 

SPC 101 Topics Covered:

• The 6 Ms of variation
• Special Cause and Common Variation
• Measuring as a Process
• Precision and Accuracy
• Precision/Tolerance Ratio
• Gage R&R (Repeatability & Reproducibility) Analysis
• Control Charts- Shewhart Rules
• Xbar R Charts
  • Stencil Printing Example
• C Charts
• Pareto Charts
• Cp and Cpk with Examples
• Minitab will be used throughout