Intent vs. Implementation

When designing anything, there's what you would like to design, and what you ended up implementing. The design intent may be elegant, beautiful, even sublime. But overlook one small issue and the whole thing can fall apart.

During the last several months, I've been embroiled in issue which directly impacts FluxCorp's bottom line -- manufacturing yield. It all boils down to a bug in the design that causes intermittent failure in a small percentage of parts. The bug is quite simple. The design intent was to add two variables, i and j, together, or i+j. But we ended up implementing was i+i. A typo? Yes. A typo that's causing months of headaches? Yes.

My example here may be a bit abstract, so let me give you a real world example. Here are two pictures of a five star hotel bathroom in India. Beautiful bathroom, except for one minor implementation flaw that renders the bathtub mostly usable. Spot the problem?