When to use DOE (Design of Experiments)?

What is design of experiments, or DOE? What do we use it for and what is it all about? We talk about when we might want to use it during the design cycle, and we do this without getting into all of the how-to and mathematical equations.

DOE is an iterative process, so don’t expect a huge once-and-done event. Practitioners recommend a general rule, that “no more than about 25% of the available resources should be invested in the first experiment.” (Montgomery pp. 17) This allows for subsequent experiments and confirmation testing.  

If we need to better understand what factors have an effect on our design output and to what degree, then DOE is a way for us to understand that. Plus, it takes into account the interactions between factors, so it is a more thorough way to experiment. It is also efficient with samples. With the multiple designed experiment recipes available, it’s worthwhile reaching out to a quality or reliability engineer to help plan a DOE. 

References:

NIST/SEMATECH e-Handbook of Statistical Methods, http://www.itl.nist.gov/div898/handbook/, sections 4.3.1 and 5.1.1, accessed October 23, 2021.

Montgomery, Douglas C. Design and Analysis of Experiments, 5th Ed. John Wiley & Sons, Inc. 2001, pp 1-11, 17, 427-430. 

For an example, visit ASQ: asq.org/quality-resources/design-of-experiments

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