FAQ Sequence Optimisation

Question: Which method should I use?

Response:This depends on the use case. For a standard sequence optimisation the method planSequence() will be sufficient. Only for specific constraints or overnight tours, the alternative methods might offer better solutions. Please contact our support team if any uncertainty still exists.

Question: My results are unexpected. What can I do?

Response: There are some various procedures to be performed:

Use our standard profiles (car, truck etc.) to validate your results.
Check your constraints: Unscheduled tour stops might lead back to conflicts respectively violations due to the combined restrictions.
Use the unscheduled order analysis parameters which leads to a corresponding result: Status and vehicle or tour violations.
Contact PTV's Support Team. Please notice the check list which is described below.

Question: How can I increase the request throughput?

Response:The PTV xServer are highly scalable that means on the one side you can increase your pool-instances adding the PTV xServer properties files on the other side you can integrate a load-balancer distributing the requests on several PTV xServer. Please read carefully the technical documentation.

Question: I have following use case: Sequence optimisation using the driver regulations according to the European regulations. Why are unscheduled tour stops listed in the result?

Response: Due to the driver regulations, several restrictions have to be considered. For instance: A driver has to take a regular rest after a regular driving period. Within a calendar week, the driver may have two extended driving periods of 10 hours and a maximum of three reduced rest periods of 9 hours. Please, validate the driver periods and take into account that the more constraints are used the more unscheduled tour stops are to be considered.

Question: In the past, I have used the parameter "wasted period". Why do I miss the parameter in the current version?

Response: There were two limit values "MaxTourWastedPeriod" and "MaxStopWastedPeriod" provided in previous versions. These values were used in the method "Savings" in order to avoid wasted periods at two consecutive tour stops. These values made sense to avoid tour stops in one tour which are geographically situated in near neighbourhood but have a big time gap. Due to the specific application, PTV decided to transfer these parameters into the engine. Hereby, they aren't provided anymore via configuration files. Anyway, using these parameters does not minimise the waiting periods and work contra productive for sequencing which probably results in unscheduled tour stops. Therefore, an alternative solution exists for sequencing to minimise the waiting period. Our technical support looks forward to assist you in getting the correct approach.