Schedule quality score issues

[vadimkerr]

1. Not clear how the score is calculated, the "Calculation methodology" section should have more info + refer to a docs page with even more info. Currently the only info available for a user is "next 90 days are taken into consideration...":

2. "Overloaded users" section is sometimes not shown when it should be. For example, sometimes it shows that "schedule has balance issues", but doesn't tell how to fix it:

3. Not clear how "overloaded" users are on the "Overloaded users" section. Currently it's binary and doesn't tell anything like (10% more on-call time than average for this schedule).

4. Next 90 days are taken into account when calculating the score, but it can yield inconsistent / inaccurate results when the rotation frequency / interval are not aligned with this 90 days window.

[raphael-batte]

1. It seems that it would be good to add as an additional parameter the calculation of the average value between users outside the working hours.

If everything is outside working hours but evenly, then there is a balance. And if the load goes in the direction of overloading someone specific, then we just show it.

2. Will be nice to collect all possible quality issues with solving tips in the documentation. Inside UI we can provide direct link to problematic place inside schedule (if its possible, fore example to focus on gaps) in the future + add link to problem resolving inside documentation.

[vadimkerr]

Related to https://github.com/grafana/oncall/issues/118

[joeyorlando]

one other minor issue to point out. See the description of https://github.com/grafana/oncall/issues/1692. I believe there is a UI race condition on displaying the schedule quality results