DOE - Design of Experiments

Design of Experiments (Taguchi Approach)-Overview

The DOE using Taguchi approach can economically satisfy the needs of problem solving and product/process design optimization projects in the manufacturing industry. By learning and applying this technique, engineers, scientists, and researchers can significantly reduce the time required for experimental investigations. 

Overall application goals:

  • Optimize product and process designs
  • Study the effects of multiple factors (i.e.- variables, parameters, ingredients, etc.) on the performance
  • Solve production problems by objectively laying out the investigative experiments

Specific Objectives:

Influence of individual factors on the performance

Which factor has more influence, which ones have less

Which factor should have tighter tolerance, which tolerance should be relaxed

Which factor influences are significant and which are not

How to allocate quality assurance resources based on objective data

Whether a supplier's part causes problems or not (ANOVA data)

How to combine different factors in their proper settings to get the best results

How you can substitute a less expensive part to get the same performance

How much money you can save if you make the design improvement


Advantage of DOE Using Taguchi Approach

The application of DOE requires careful planning, prudent layout of the experiment, and expert analysis of results. Based on years of research and applications Dr. Genichi Taguchi has standardized methods for each of these DOE application steps. Thus, DOE using Taguchi approach has become a much more attractive tool to practicing engineers and scientists.


Overall advantage

DOE using Taguchi approach attempts to improve quality which is defined as the consistency of performance. Consistency is achieved when variation is reduced. This can be done by moving the mean performance to the target as well as by reducing variations around the target. The prime motivation behind the Taguchi experiment design technique is to achieve reduced variation (also known as ROBUST DESIGN). This technique, therefore, is focused to attain the desired quality objectives in all steps. The classical DOE does not specifically address quality .

Experimental procedure

The Taguchi method is used to improve the quality of products and processes. Improved quality results when a higher level of performance is consistently obtained. The highest possible performance is obtained by determining the optimum combination of design factors. The consistency of performance is obtained by making the product/process insensitive to the influence of the uncontrollable factor. In Taguchi's approach, optimum design is determined by using design of experiment principles, and consistency of performance is achieved by carrying out the trial conditions under the influence of the noise factors.