Working with outline levels in Project formulas | MS-Project forum

Hi Gianluigi

Thank you for your question. One way that might answer this would be first to create your formula in the customised field. Just below the formula setting in the Custom Fields dialogue box there is an additional option to control how the calculation should behave on summary rows.

You might want to experiment between roll up (which brings the values up from the lower level) or use Formula which applies the formula directly to the higher level summary task.

Let me know if that produces the results you are looking for.

Kind regards,
Andrew