Taguchi’s 3 Fundamental Concepts

Taguchi’s 3 Fundamental Concepts

Taguchi may be best known for the variation of design of experiments that bear his name. Yet the impact of his work is felt across the product life cycle and all of the quality field.

Building on Deming’s observations that 85% of poor quality is due to faulty processes and only 15% due to the worker, Taguchi focused on creating robust processes.

A robust system is one that tolerates the daily and seasonal variations of the environment, machine wear, and equipment part-to-part variation, etc. A robust system operating in the range of real world conditions.

Taguchi basic philosophy has three concepts:

1. Design quality into the product.
2. Achieve quality by minimizing deviation from the target.
3. Measure the cost of quality as a function of deviation from the standard (Taguchi loss function).

Let’s explore each of these a bit more.

Design quality into the product

As a brand new manufacturing engineer I was asked to write a letter to a customer explaining why a product they purchased from us failed. My first inclination was the design of the product wasn’t appropriate for their use conditions.

I knew that in manufacturing we could make a product almost as good as the design. In essence we could only make actual products that would not be…