Getting precise about tolerance | Seth’s Blog

Tolerance is an engineering term. When the parts of a car are made to a low tolerance, that means that they fit perfectly. A modern Lexus is a better car than a 1976 Nova because relentless improvement means that the parts are more exact.

Tolerance is a design term. When a system can tolerate non-perfect users and interventions, the interoperability increases and so a high tolerance design is often seen as more successful.

Tolerance is a systems term. When we build a community that can thrive when everything isn’t exactly the same, the community is more likely to produce connection, health and well being.

Tolerance is a personal-interaction term. If our dealings with someone don’t go well, we’re still able to recover and even produce useful work or play together if our tolerance for frustration is high.

Tolerance is a disability term. When a user brings different skills, languages, boundaries and skills to a system, a tolerant solution allows them to thrive.

And tolerance is a climate term. When the built world becomes more resilient, it not only survives the unexpected, it doesn’t make things worse.

Low tolerance manufacturing takes dedication and skill. And it permits us to be high tolerance in the rest of our processes. An organization that tries to limit incoming participation and has rigid rules probably doesn’t trust the tolerance of their underlying stack.

It’s interesting to put all this together and think about Lego blocks.

For generations, Lego pieces have been made to low tolerances. They stick together and come apart with precision. This allows them to work extremely well with any other part the company has ever made. And because of their long-lasting simplicity, they can be used in ways the creators of the toy didn’t expect… to furnish an aquarium or to build life-sized sculptures, for example.

People aren’t toys, and the variations we deal with are a bit harder to predict. And changing systems and climate are less predictable than most toddlers, so there are surprising variations there as well.

The thing is, tolerance is achievable. And tolerance creates value. But it helps to name it, measure it and seek it out.

February 27, 2025