Monthly workload summing each phase from each project

Hello,

I'm looking for the best approach to represent monthly workload for all our projects considering theoretical workload (field [Workload [%]]) for each phases.

I've a data set looking this:

What I'm looking to do is to have the full workload month by month.

NB: At this stage Owner and Activity are just for information now (later, I'll had the possibility to filter by Owner)

NB2: Workload is always the same by project phase:

=> for each single project, earliest start date and latest due date by phase should be considered

The 1st step is probably for each line of my table to identify the earliest start date/latest due date by phase for each project (I've been able to do it):

Next step would probably be to build a virtual (or real) table from earliest start date (here: August 23) to latest due date (here: October 24) and calculate each month the workload by project and phase according below illustration:

Would someone know how I can get there (or simpler approach to get the "Total worload by month" in my upper example)?

Thanks in advance.

Have a great week-end.

Fab