PM Actions can be planned between Earliest Start and the Latest Finish dates indicated on Maintenance Plan lines. These dates can be adjusted for the entire PM Action using the fields Expand Backward and Expand Forward in the Maintenance Triggers tab. Note that Maintenance Planning and Scheduling solution does not plan PM actions outside planning window.
PM Action should be calendar based.
Planning window for all the Maintenance Plan lines adjusted.
Earliest Start = Due Date - Expand Backward.
Latest Finish = Due Date + Expand Forward.