Sorting data for use in a pivot chart. Can anyone help?

Hi everyone,

I have a long list of calibrations that I need to do for a system. A few hundred. I need to group them into the general different areas for viewing in the pivot table.
I also have to ensure that they have a number assigned to them to ensure they are performed in the correct order.

To help with this I have a column of prerequisite conditions that have to be met (ie other calibrations). Is there any formula/way that could at least sort the calibrations putting them below their prerequisite calibrations? It would make it a lot easier when numbering them.

Thanks

It would help if you could upload a copy of your workbook. Be sure to remove any sensitive or confidential data before uploading.