Calculate the number of hours spent in excel - how to do it?

Question

excel

Good afternoon!
It was necessary to solve one problem in Excel: there are tabs for employees and a general directory of projects (on which employees work).
For each employee, the table looks something like this:
Project (drop-down list from the directory on a separate tab) / Number of hours (number)
What function can I use to collect data on all hours for a specific project from the directory?

Answer 1

Looks like you need to use the
SUMIF function
Example:

Answer 2

Move everything to 1 tab and use a pivot table.
In order for the tables on employees to be updated, you can use formulas that are linked to the employee tabs.