Robust process and product design concepts

Learning objectives

• Explain the purpose of robust process and product design concepts in a garment-factory improvement project.
• Apply the described method to a representative shop-floor situation.
• Recognize the common mistakes and how to avoid them.

Concept

Robust design maintains CTQ performance despite realistic noise such as operator, material, environment, and wear variation.

Separate control and noise factors, test boundary conditions, and center settings away from failure edges.

Simplify interfaces and design tolerances/functions for manufacturing reality, not laboratory ideals.

Garment-factory example

A seam construction remains strong across fabric stretch lots, trained operators, needle wear, and humidity within approved ranges.

Method

1. List realistic noise.
2. Analyze sensitivity via DOE evidence.
3. Redesign process or product.
4. Stress-test at boundaries.
5. Define safe operating window and controls.

Common mistakes

• Setting a single optimum with no margin.
• Compensating weak design through 100% inspection.