How many id’s for each activity?

First of all you need to understand that power project is a graphically based programme.

You have bars Which are single activities on a gant chart line. As you add activities in your programme PP gives each one a line number (bar ID) at the same time PP allocates a unique ID to this bar, the unique ID does not change whereas the bar (or line no) changes if you add or move the bar.

In PP you have the ability to split bars into tasks and the same numbering logic applies to the tasks.

A way of checking this is to add columns to the spreadsheet for each token.

Thank you for explaining. Graphics based and hence I had a feeling that Power Project would be more user friendly. But....