Type: Penalty
Category: STK
CHE Types: All
Reference: perfect match threshold
Description: Threshold for the STKPFM (on page 1) (perfect match) penalty when both containers have estimated move times. If the container being decked satisfies the requirements for the STKPFM penalty and has an estimated move time (EMT) at least this many minutes (PMMTTH) before containers already in the stack, N4 uses the perfect match penalty (STKPFM). Otherwise, N4 uses the probable rehandle penalty (STKREH). In other words, the decked container is only a perfect match if it is going to be moved out earlier than the stowed containers EMT - PMMTTH.
This ensures that no new rehandles are created when a planned load is put over another planned container or if the outbound sequence changes slightly.
For example, if PMMTTH is set to 30 (default value) and:
Stowed container A already in stack S is a load move with estimated move time (EMT) of 9:15.
Decking container B has an EMT of 9:00.
Both containers have same stacking factor and satisfy the STKPFM requirements.
Prior to this threshold, N4 would consider container B a "Perfect Match" for stack S since it should be moved out earlier than container A (by 15 minutes). However, now with the PMMTTH threshold, the EMT for container B is too close to the EMT of container A (15 minutes, which is less than the PMMTTH threshold of 30 minutes). There is a possiblity that container A could be the first to move and could be blocked by container B. Therefore, instead of setting stack category to "Perfect Match" (STKPFM penalty), N4 uses the "Probable Rehandle" penalty STKREH, which is a much higher penalty.
The value you set applies only to decking in N4. For Assign Position or other XPS decking, the behavior does not change. XPS uses a hard-coded threshold value of 30 instead of this penalty. However, you can change the PMMTTH penalty value in XPS.
This penalty is primarily for use by semi-automated sites.
Default: 30
Module: Expert Decking