During my session on 24 Hours of PASS 2015 Russian Edition I was asked about the Import database wizard in SQL Server Data Tools. The particular option is “Maximum files per folder”.
This option allows you to split the whole number of database objects to separate folders with a specified quantity of these objects. The dropdown list contains three values: 100, 500 and 1000. You can enter the value manually, but the minimum is 20 (SSDT auto-corrects it if you enter a quantity less then 20).
As a result you will get the following structure in you database project.