If you have created a budget and assigned it to a project, you can restrict the employees, activities and expense items that can be used on this project to the ones specified in the budget. You need not assign them to the project again via Project Assignments if you have already created the budget. All you have to do is add the below three rules to your project:
- Restrict expense entries to budgeted expenses
- Restrict time and expenses to budgeted employees
- Restrict time entries to budgeted activities
This achieves the same effect of limiting the employees, activity and expense items on the project, without the need to create project assignments. Check the Core Help for more on these project rules.