Itamar Gilad shares a healthy critique of the Impact/Effort prioritization matrix that is so ingrained in every product manager’s brain:

As straightforward as this all seems, there are major problems with Impact/Effort prioritization that cause us to pick the wrong winners. Most importantly Impact/Effort analysis requires us to make somewhat reliable predictions on future events — the effort we will require to complete a task and the value that will be delivered to users and/or to the company once completed. As it turns out both are jobs we’re exceptionally bad at.

He doesn’t say we need to stop using it though, just that we need to move the borders of the matrix around a little bit. It’s also worth noting that there is no “one size fits all” prioritization method. I’ve written about different prioritization techniques, and am a proponent of choosing and adapting the ones that work best within the culture of an organization.