Resource Property Editor

The number represents the maximum cell delay from DATAIN and PADIO port and it generated directly from timing analysis tool (Classic Timing Analysis or TimeQuest Timing Analysis). Resource Property Editor isn't targeted for changing delay numbers. It's used for making last-minute engineering change orders on the post-fitting netlist. For example, if you have minor changes that you need to make on your design, then you can change it in Resource Property Editor without having to recompile. As for how to change delays, you need to specify Timing constraints as assignments in .qsf file and recompile.