Imagine two countries working together to build a bridge across the river that separates them. Each country starts building from their own side, engineering their half to meet perfectly in the middle.
Simple enough, right?
To make sure both halves line up, the teams agree to build to the same height above sea level. Logical. Measurable. A clear shared standard.
Except the bridge halves didn’t meet in the middle. They missed.
What happened?
Here’s where it gets interesting. There is more than one sea in the world. Switzerland measured from the Mediterranean. Germany measured from the North Sea.
The teams knew this going in. They weren’t caught off guard. They adjusted their calculations to account for the difference.
And yet the bridge halves were still different heights when they finally got close enough to see each other across the river.
There was an error with a mathematical sign. In mathematics, a sign indicates whether a number is positive or negative. A small thing. Easy to overlook. But in this case, instead of canceling out the height difference between the two halves, that sign error doubled it.
The error wasn’t caught until workers could physically see the misalignment from across the water. This is the real story of the High Rhine Road Bridge between Switzerland and Germany.
What does this have to do with project management? Everything.
1. Shared vocabulary doesn’t always mean shared understanding. Both teams were using the term “sea level.” Both teams were confident they meant the same thing. They didn’t. On your projects, assumptions like this hide in plain sight, lurking in requirements documents, in handoff conversations, in the spaces between what was said and what was heard. Part of a project manager’s job is to surface those assumptions before they become expensive surprises.
2. Knowing a risk exists doesn’t mean it’s fully managed. The teams identified the sea level discrepancy early and took steps to correct for it. That’s good risk mitigation. But risk mitigation isn’t a one-time event; it needs to be verified. The mathematical correction introduced a new error that went unchecked. Identifying a risk and addressing a risk are two different things. Following up to confirm the fix actually worked is a third.
3. Even careful, experienced people make mistakes. A sign error. One character. Enough to misalign an international infrastructure project. This isn’t a story about negligence. It’s a story about the reality that mistakes happen even when everyone is competent and well-intentioned. A good project manager doesn’t build a plan that assumes perfection. They build one that can catch and recover from imperfection.
4. The later you catch a mistake, the more it costs. In this case, a solution was found that avoided additional costs. The closer you get to the finish line before discovering a problem, the fewer options you have and the higher the stakes. Early detection is everything. Regular check-ins, milestone reviews, and progress tracking aren’t bureaucratic busywork. They’re how you catch the sign error before the bridge halves are visible to each other across the river.
Projects don’t fail because people are careless. They fail because complexity is hard, assumptions are invisible, and even good plans have gaps.
If you want a project manager who understands that things go sideways sometimes — and knows how to build the kind of structure that catches it early — let’s talk.