If the departments that must sign off on a project are the same for every project you can set up a default structure for every new project. If each project requires a different set of departments to sign off you can do it through data entry, but either way you *should* use a junction table to connect tMainRec to tDepartment
i.e.
Code:
tblMainDeptJunction
MDJ_ID MR_ID D_ID Pers_ID Signoff_Date ---> other signoff related fields
PK = Primary key
FK = Foreign key
Where MDJ_ID is the PK of the table, MR_ID is the main record FK, D_ID is the department FK, Pers_ID is the personnel FK and the signoff_Date is self explanatory