The Mizenboushi is a Toyota concept to prevent defects. He proposes to put himself in a position of anticipation from the design phases to ensure a robust design and flawless quality.
Le Mizenboushi is a Japanese term created by Dr. Tatsuhiko Yoshimura, then consultant at Toyota, to prevent quality problems. Through this concept, the challenge is to prevent defects from the design phase of a product. He proposes to change paradigm from a tested and controlled quality to a quality designed1.
This concept is based on an internal Toyota study showing that 48% 2
problems can be predicted upstream and could be avoided. The challenge is to be in a position of anticipation by having a proactive problem prevention activity.
Les 3 principles
Aussi appelé GD3, Mizenboushi is based on 3 principles of reflection and operation to ensure the goal of designing robust products.
Mizenboushi relies on the tool QFD, which links the product functions to customer expectations, and proposes to follow the following best practices: :
- Identify and reuse past technical solutions that are known to be robust and reliable.
- Identify, minimize and manage changes in the conditions of use or the environment of use.
- Minimize the number of changes on a product.
- Understand interactions between different subsystems / components…
- Designed with features that took into account emerging issues.
The second principle is based on creativity and open-mindedness to control design risks, especially by taking into account and analyzing changes in design as well as in the conditions of use of the product.
Through multidisciplinary team work, we use the tool DRBFM. Relying on a FMEA, it allows to be more creative and to take into account specific criteria for the use of the products. With this tool, we will structure the design reviews and exchange on factual and reliable data.
This last principle proposes to set up a validation process based on test analyzes. Each subset must be disassembled for testing and control. The tool used is DRBTR, Design Review Based on Test Results. It allows to document the tests, to take into account the effects for the customers and to determine if corrective actions are necessary.
1 – R. Seyler (2006) – GD3
2 – Toyota (2006) – Mizenboushi, Toyota’s quality problem prevention method
C. Carlson (2012) – Effective FMEAs
T. Yoshimura (2002) – Toyota styled Mizenboushi method – GD3 preventive measures – How to prevent a problem before it ocurs
G. L. Outwater (2013) – Mizen Boushi method support of robust design
A. Kapust, M. Schorn (2005) – Im fluss : wie Toyota von DRBFM profitiert