Hi @jachlt
There is no such "best practice":
Planned hours = the work that needs to be done
Duration = time frame in which to do the work
Those values are specific to your case and process.
- It's possible to do 6-7hrs work in a 8hr day
- It's sometimes the case that you do but 2hrs of work due to meetings, interruptions etc.
Talk to the people actually doing the work instead of looking for "best practice"