Questions: Iterative Design and Continuous Improvement

Question 1

An engineer builds three prototypes of a water pump, each one better than the last. What drove the improvements between versions?

• A. Random changes to see what happens
• B. Test data from the previous version showing where performance fell short
• C. Making the pump bigger each time
• D. Copying a competitor's design

Answer: (B)

Iterative design uses test data to identify specific weaknesses. Each new version targets those weaknesses while preserving what already works. Changes are driven by evidence, not guessing.

Question 2

The goal of iterative design is to achieve a perfect final product.

• T. True
• F. False

Answer: False

The goal is to achieve a product that meets all requirements within the given constraints. Perfection is not achievable -- engineers iterate until the design is good enough, then stop. Knowing when to stop is part of the skill.

Question 3

Why do early iterations of a design typically show larger improvements than later ones?

Model answer: Early iterations fix the biggest, most obvious problems, which produce large performance gains. Later iterations address smaller, subtler issues, so each improvement is smaller. This pattern of diminishing returns is natural in optimization.

The biggest problems are easiest to identify and fix. Once major issues are resolved, remaining improvements require more effort for less gain. This is why engineers set target requirements rather than pursuing infinite improvement.