Issue matching (dates) MS Project Capacity & demand to calculate utilisation

Hello artfulmunkeey 

here another approach.

Check it out

let
    Demand = 
    let
	Source = #table
	(
		{"Proejct ID","Resource ID","Date","Demand"},
		{
			{"Project 1","Resource 1","Jan-20","100"},	{"Project 1","Resource 1","Feb-20","80"},	{"Project 1","Resource 1","Mar-20","120"},	{"Project 1","Resource 2","Feb-20","100"},	
			{"Project 1","Resource 2","Mar-20","80"},	{"Project 1","Resource 3","Jan-20","100"},	{"Project 2","Resource 1","Feb-20","20"},	{"Project 2","Resource 1","Mar-20","30"},	
			{"Project 2","Resource 2","Mar-20","20"},	{"Project 2","Resource 2","Apr-20","50"},	{"Proejct 2","Resource 3","Feb-20","100"}
		}
	),
    changetype = Table.TransformColumnTypes(Source, {{"Demand", Int64.Type}}),
	AddMonthYear = Table.AddColumn(changetype, "MonthYear", each Text.From(Date.Month(Date.From([Date]))) & "-" & Text.From(Date.Year(Date.From([Date])) ))
    in
	    AddMonthYear,

	Capacity = 
	let
	Source = #table
	(
		{"Resource ID","Date","Capacity"},
		{
			{"Resource 1","01/01/2020","8"},	{"Resource 1","02/01/2020","8"},	{"Resource 1","03/01/2020","8"},	{"Resource 1","04/01/2020","8"},	{"Resource 2","01/01/2020","8"},	
			{"Resource 2","02/01/2020","8"},	{"Resource 2","03/01/2020","8"},	{"Resource 2","04/01/2020","8"},	{"Resource 3","01/01/2020","8"},	{"Resource 3","02/01/2020","8"},	
			{"Resource 3","03/01/2020","8"},	{"Resource 3","04/01/2020","8"}
		}
	),
	changetype = Table.TransformColumnTypes(Source, {{"Capacity", Int64.Type}}),
	AddMonthYear = Table.AddColumn(changetype, "MonthYear", each Text.From(Date.Month(Date.From([Date]))) & "-" & Text.From(Date.Year(Date.From([Date])) ))
	in
		AddMonthYear,
	Join = Table.NestedJoin(Demand, {"Resource ID", "MonthYear"}, Capacity, {"Resource ID", "MonthYear"}, "Capacity"),
    #"Aggregated Capacity" = Table.AggregateTableColumn(Join, "Capacity", {{"Capacity", List.Sum, "Sum of Capacity"}})
in
    #"Aggregated Capacity"

Copy paste this code to the advanced editor in a new blank query to see how the solution works.

If this post helps or solves your problem, please mark it as solution (to help other users find useful content and to acknowledge the work of users that helped you)
Kudoes are nice too

Have fun

Jimmy