S-162-V1-EN
Piece validation errors are encountered when there are pieces in your schedule that violate your preferences or are uncuttable for other reasons.
The piece validation tool described in this article is a valuable source of reference in those cases, so you can use it along with this article when troubleshooting the errors described below.
Troubleshooting scenarios
Piece cutting-related issues usually show up during optimization. The optimization error in this case looks like this:
"The action could not be completed because X time period(s) within the vehicle block(s) are not covered by any valid duty piece(s). To resolve the issue, go to the schedule and select the affected time period(s). The piece validation icon at the bottom left of the tooltip will provide further details."
"These are the vehicle IDs affected, followed by the time periods that are not covered:"
As the error indicates, you will need to check the listed vehicle IDs and the affected time stretches by using the piece validation tool on them.
Below you will find some of the most common issues that can invalidate a piece.
Mid-route relief point not defined
If you want a piece to be cuttable mid-route, that route should have relief points other than the start and end stops.
A piece is not considered valid if a mid-route relief point was not defined in the timeplan or dataset.
To fix this, find the stop in question in the timeplan or dataset and mark it as a relief point.
To learn how to edit stops in the timeplan, check this article.
In the example below, the piece violates the Continuous break preference unless its last trip is cut mid-route. The rest of route 21 is picked up by another duty in that case:
Relief point preferences
If you want to only allow certain relief points for piece cutting, you can do that in Relief point preferences. Otherwise, all relief points set in Planning plus terminal (start and end) stops will potentially be used for that purpose.
In the example below, route 21 has 4 relief points: the terminal stops a and d and mid-route relief points b and c. Unless specified otherwise in the Relief point preference, all those relief points can be used. The lower image shows that we’ve configured the Relief points preference in a way that only the stops b and d are allowed for relief.
If the validation error on a piece points to Relief point preferences, open those preferences and make sure that the points where you expect a piece to be cut are set as relief points for their respective routes.
Other possible relief point issues:
Missing fallback relief point rule that depots are allowed as relief locations.
Overlapping rules for the same route - setting multiple relief point rules for the same route, will result in the route not having any allowed relief points.
Overlapping time ranges. Keep in mind that in every time range, all relief point preferences must be valid.
To define the following:
Relief point A is valid only from 06:30 to 21:45
Relief point B is valid only from 06:45 to 21:15
You need to set 3 relief preferences like this:
06:30 - 06:45: Only A
06:45 - 21:15: A & B
21:15 - 21:45: Only B
Break preferences
Continuous break rules can interfere with vehicle piece cutting because a piece can be longer than the maximum time without break value. In that case, adjusting the value will fix the issue.
Custom duty preferences
Custom duty preferences, namely Limit short pieces and Limit long pieces affect piece cutting as well. Use the tool to see if any potential pieces are invalid and adjust the preferences accordingly.
You can also use Crew Relaxation to make exceptions:
The example below means that if a piece is not valid according to Limit short pieces, but it is the only piece the algorithm can produce, the limit will be ignored.
Locked vehicle pieces
If the adjacent piece (on either side) is part of a locked duty, it makes the piece uncuttable.
Solution: unlock the duty and try optimizing again.