I think visually, so here's a way I like to communicate performance
thresholds. There are a bunch of dimensions that might make an
application behave differently. Test against those dimensions and plot
the thresholds of each one. Here are some that I made up, for a
The goal is to have all real world scenarios fit inside your polygon. So
here's a real world use of the application that we can handle no
And here's one that pushing the limits a bit more.
And here's one we didn't anticipate, or our app should never have
allowed because it's clearly not going to work.
There are a few caveats to visualizing performance thresholds this way:
- We might have missed a dimension. Turns out that the phase of the
moon dramatically affects performance and that wasn't a dimension we
tested along. Oops. This is no fault of the visualization, but can
most definitely happen (and in fact did just happen and prompted
- Dimensions might not be independent. For instance, if you have more
memory, the maximum allowable job size may go way up. That's hard to
capture here, and often isn't necessary. If you're giving guidance
to a customer on performance, skip the nuance and stick to
- We might not really understand some of the boundaries as well as
this diagram indicates. With performance testing, it's rare that you
can categorically say that 1,000 visitors works fine but 1,001
visitors brings down your website. Build in some buffer
- And remember, there is a difference between an app theoretically
supporting a threshold and actually testing to that threshold.
Theoretical boundaries need be called out clearly and separately.
Like what you read? Join the newsletter and get updated when there's something new.