The Five Stages of DOE

Design of Experiments, or DOE, is a powerful mathematical tool that can be successfully applied to areas of new mold trials and to trouble-shoot potentially challenging processes. Experimental design techniques can be utilized by anyone with a fundamental understanding of injection molding.

There are five primary stages for conducting a designed experiment. These are planning, selecting the tests to run, conducting the experiment, analyzing the data, and then confirming the results.?Here is an overview of each stage:

Step 1 - PLAN

The first step is planning the experiment. This includes defining the objective, selecting the factors to be studied, and determining the settings, or levels, for each factor. In this phase, we also determine the response of interest. The response of interest is the variable we are trying to determine by running the experiment. We will refer to this simply as the “response” throughout these lessons.

Step 2 - SELECT OA

The second step is selecting the series of tests to be performed. In this phase we also need to determine the number of repeat samples for each experiment.?In a designed experiment a mathematical set of tests, referred to as orthogonal array (O.A.), are used for this step.

Step 3 - CONDUCT

The third step is conducting the experiment. It is important to have a written plan or protocol in place and that someone from the team is present while the trials are being conducted to note any deviations from the experiment protocol.

Step 4 - ANALYZE

After conducting the experiment, the fourth step is to measure the responses of interest and analyze the results. In this stage you will utilize the graphs and charts along with the statistical output generated from the software used for the experiment.

Step 5 - CONFIRM

The fifth and final step is the confirmation phase. By making a prediction of the best setting for each factor and then trying this setting one or more times, you can confirm the results.?Verifying the optimized process set up is essential for maintaining part quality.

Design of Experiments (DOE) can help injection molders with new tool trials and to trouble-shoot problematic processes. Having a repeatable and robust process is essential prior to conducting a designed experiment. Understanding the five primary stages of conducting a designed experiment can provide injection molding professionals with the ability to utilize this powerful tool.

Kruse Training offers a full section of Processing lessons. You can purchase any of our?individual lesson?or?a?full set?of an category of lessons.

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Kruse Analysis, Inc. has been providing CAE simulation services to the plastic injection molding industry since 1995. By using advanced?Moldex3D?technology, Kruse helps customers troubleshoot from product design to development, optimize design patterns, shorten time-to-market, and maximize product return on investment (ROI). For more information, visit?www.kruseanalysis.com

Kruse Training, Inc. offers a state-of-the-art online knowledge and training solution that use 3D process simulation technology to demonstrate cause and effect of molding behavior. This interactive training program illustrates how "The Circle of Knowledge" between the part designer, mold designer, and process engineers works in the real world of plastic mold and design. For more information, visit?www.krusetraining.com