Microsoft Project only supports the following ISO time units: minutes, hours, days, weeks, and as of Microsoft Project 2000, months. If you use other time units in your projects in the Project System (PS), you must define conversion factors.
1. To branch to the PS Time Unit Definition dialog box, choose Time units.
2. Use the arrows at the bottom of the box to navigate between existing settings. The first five cannot be changed, these are the ISO time units recognized by Microsoft Project.
3. To create a new time unit, choose New.
a. ISO time unit, for example, ANN
b. Conversion factor, for example, 52
c. Microsoft time unit, for example, week.
Ensure that the correct ISO unit and the corresponding conversion factor is entered. To check this in the SAP system (SAP R/3 or mySAP ERP), use transaction CUNI.
5. Choose Save
6. To exit the Time Unit Definition dialog box, choose Close.