
Work is a rollup field, so if a project has subitems you cannot set work at both the subitem and project level. Budgeted Work (I think this used to be called budgeted hours) does not rollup and is designed to be a manually set field that you can set at any level. I would recommend using the Work field whenever possible since that is what the system is expecting for processing other fields like Work Variance (difference between Actual Effort and Work).