Hi Inba,
The primary difference between the two analyses you list is the part temperature recognized during the cooling analyses. Because the cooling analysis is a steady state analysis, it associates a value for the temperature of the part cavity.
If you run cool+fill+pack+warp it will assume that during the cooling analysis that the part exists in the cavity completely filled and at melt temperature. It will then calculate the temperature of the tool and the effect on the part based on your cooling design. It will then run the fill and pack analysis filling your part and finally the warp to calculate deflection based on existing stresses and shrinkage during the previous analyses.
If you run fill+cool+fill+pack+warp the only difference is the temperature assigned to the part cavity in the cooling phase. Rather than running with a universal melt temperature for the whole cavity, it runs a fill analysis to calculate the temperature of the part in different regions and applies that. It provides a higher level of refinement for the analysis, but in many cases the temperature difference overall is so small it's negligible.
-Justin
Justin Courter
Premium Services Specialist
Premium Support Services
Autodesk, Inc.