Software R&D manager Yin & Yang

Taking on-board "the fastest way to do something is to not do it at all"  (is this an Alistair Cockburn quote?) I'm thinking that a software R&D manager's performance might come from how many things a team does not have to do.

A yin and yang relationship with a software developer who's performance could be measured by how much they (or help a team to) deliver working functionality and a manger.

How do you measure what was not done?