What is the purpose of the Jira Portfolio stages and skills' percentages?

[Ronny Hanssen]

This question is in reference to Atlassian Documentation: Understanding stages and skills

The JIRA Portfolio adds the concept of percentages for the stages and skills, but the documentation doesn't explain how this impacts planning. I also see that for issues I can specify specific skills, but when doing that I will assign either story points or days/hours. So, why the percentages?

[Rita Lewitt]

PS, the percentages are used as a default setting to break the estimate up across the skills.  As I mentioned above, you can manipulate those values manually by changing them in the estimate field in the scope listing.  (Assuming Portfolio 2.0)

[Rita Lewitt]

A suggestion is to customize the time allocated to that skill that is either not needed or doesn't need to be what % is defaulted to.  In the Scope listing, add the Estimates column to the list.  Then modify the allocations manually in the list.  In this way I have been able to set a given skill to 0 and remove those errors if that skill is not needed. 

[AdilusBNC]

Same question here, why do we always end up with the following error message: Missing Skill for sub Task.

Even if we have covered all the skills for our only stage by the teammates (virtual users), some of the Sub Tasks and corresponding Stories cannot me planned in the Portfolio because of that error.

The work around is to define one or more user with all the skills.

Why doesn't it accept to plan according to user availability based on the fact that our team does actually cover all the stage's skills?