Create summary data with concatenated cells

Hello,

I have a sheet like:

category | project | priority | team | when | status | who | notes

---------------------------------------------------------------

cat1 | project1 | high | core | 24 Q1 | high | bill | etc

cat2 | project2 | high | core | 24 Q2 | high | james | etc

cat2 | project2 | high | core | 24 Q2 | high | michelle | etc

cat3 | project3 | high | core | 25 Q1 | high | michelle | etc

cat3 | project3 | high | core | 25 Q1 | high | jimmy, ashley | etc

I want a new summary table is:

project | when | who

----------------------

project 1 | 24 Q1 | bill

project 2 | 24 Q2 | james, michelle

project 3 | 25 Q1 | michelle, jimmy, ashley

Consider:

* A row can have an empty "who", still bring the project over

* A row can have multiple names in the "who" column

* All "projects" w/the same name will have the same "when"

* A "project" can be repeated in the first row with different names on each row

* I want to be able to expand the original project list and auto-update the summary

I'm a bit basic with excel, this is actually a google sheet, so please bare that in mind.

Thanks!