Utilization by Department

Hi Everyone,

In company, we are using Timesheet Application. We are taking their datas from sharepoint. And visualizing them at Power BI. So each week new datas are coming from personnal. Here I have a Calculated Table. In this table, I am measuring utilization by personnal. These are utilization of the personnal by week. However, I also need to measure them by Department. Each week measuring by itself. So it is empty, if that week didn't come.

DAX is like that;

Table =
SUMMARIZE (
RateListBU;
RateListBU[Birim];RateListBU[Rol];RateListBU[Personel];
"Week 1"; DIVIDE (
CALCULATE (SUM ( TimeSheetPlusListBU[Billable Hours] ); TimeSheetPlusListBU[Period] = "Week 1");
SUM ( RateListBU[Week 1] )
);
"Week 2"; DIVIDE (
CALCULATE (SUM ( TimeSheetPlusListBU[Billable Hours] ); TimeSheetPlusListBU[Period] = "Week 2");
SUM ( RateListBU[Week 2] )
);
"Week 3"; DIVIDE (
CALCULATE (SUM ( TimeSheetPlusListBU[Billable Hours] ); TimeSheetPlusListBU[Period] = "Week 3" );
SUM ( RateListBU[Week 3] )
);
"Week 4"; DIVIDE (
CALCULATE (SUM ( TimeSheetPlusListBU[Billable Hours] ); TimeSheetPlusListBU[Period] = "Week 4" );
SUM ( RateListBU[Week 4] )
);
.

.

"Week 53"; DIVIDE (
CALCULATE (SUM ( TimeSheetPlusListBU[Billable Hours] ); TimeSheetPlusListBU[Period] = "Week 53" );
SUM ( RateListBU[Week 53] )
);
)

With each week, new week utilization value by personnal is creating. How can I calculate utilize by departmant?