Process Path Modification



Path Modification allows the Applicants to ask for the change of some elements on the already finally agreed path. Such modification can be requested for one part or for the whole validity period of the dossier. The pre-condition for the start of the Path Modification process is dossier in the Active timetable phase (final phase of each Path Request process). The path Modification process is then started by any Applicant (initiator) at any time. PCS constraints that CANNOT request a change for days that are in the past!

The whole process consists of the following phases:

  • Path Modification Conference – Applicant phase
  • Path Modification Request – Milestone
  • Path Modification Elaboration – IM phase
  • Path Modification Offer – Applicant phase

The dossier does not have to run through all of the phases mentioned above. The leading Applicant has always the right to withdraw the modification request and go back to the original state into the Active timetable phase. The dossier is converted back to the original path request process type. Further information about path modification process steps could be found under the description of phases.

How to start the process

First, the Applicant has to press the"Submit path modification conference" button where the process will start with a wizard window. It works in all process types the same way.

An applicant in the first/last territory opens dossier in Path Modification Conference and applies the required modification on the selected sub-path. 

Path Modification types

The following Path modification types are available in the system:

  • Additional days
  • Cancelation of days
  • Modification of departure or arrival time
  • Modification of route
  • Modification of train parameters
  • Border/Handover/Interchange times adaptation

Affected pairs

Initiator Applicants have the option to mark manually their partners to be affected. However, if the changes are done only internally without any impact on the partners, the neighboring Applicants should not be bothered. Of course, PCS is checking the changes that the initiator Applicant makes and if there are changes that are affecting the border, the system will downgrade the partners' light to yellow automatically.

    Initiator Applicant is marked with the following symbol: 

    Affected pair marked with the following symbol: 

    Edit timetable

    Once the reason for the path modification and the involved pair (s) have been determined, the Applicant timetable will be editable for the initiator Applicant.

    Changes could be:

    • Times
    • Parameters
    • Calendar

    Accept/Reject changes

    Affected Applicants/IMs should check the changes that were made by the initiator Applicant the dossier in order to submit it to the next path modification phase. 

    If for some reason, one of the partners rejects and changes the acceptance indicators to red than must add a mandatory comment to explain the reason for the action.


    When the path modification process started PCS saves the action automatically into the comment area including the selected path modification types.

    Also the same happens if an involved parties reject the offer and enter the reason for action:


    Validity period fully in the future

    The following example will show the modification process in the Late Path Request process type.

    Start Path Modification

    In our example, the leading Applicant is LTE-HU, but the Path Modification is started by the involved Applicant RCA.


      The Next step is to select the reason for the Path Modification indicating it with the type of modification. In our example, we will modify the timetable, so we choose the modification of the departure/arrival timetable and the modification of the train parameters path modification types. It is possible to select multiple items for path modification reasons.


      Editing timetable

      The applicant can select either to edit the timetable or edit the train parameters, PCS opens the timetable in "edit" mode as in Open and Harmonization phases. 

      The system indicates on the subpath that the process has started, it uses the path modification word abbreviations( PM) :


      After submitting the Path Modification request the dossier arrives at the Path Modification Conference phase and the light of RCA has been downgraded to yellow, for ÖBB-I has been downgraded to blue.

      Change timetable 

      Changes were made, the timetable was shifted 2 minutes earlier in each Austrian station.


      We changed the timetable on the border section that should result in yellow lights on the partners' side:

      Submit Path Modification request

      When each affected Applicant accepted the dossier, the initiator Applicant can submit the Path Modification request.

      Path Modification Request

      This phase is a milestone.

      Path Modification Elaboration

      When the initiator Applicant has submitted the path modification request the dossier arrives into the Path Modification Elaboration phase.


      IMs lights downgraded to blue as in the "normal" Path Elaboration phase. They should check the request for changes similar to any other path request and provide a timetable with the same possibilities as in Path Elaboration. At the end of their phase, the pair of the initiator IM should send the Path Modification Offer when each affected IM lights are green.


      The decision on Path Modification Offer

      Applicants can check the received offer for their Path Modification request and they can make their decision. The usage of the acceptance indicators (lights) is the same as anytime else. At the end the initiator Applicant has three options:

      • Ask for offer adaptation: in case the offer is not suitable for the Applicants, but only a couple minor modification is missing, Applicants can decide to give it back to the IMs for finetuning the offer. It can be done every time when they receive an offer in Path Modification. When the initiator Applicant clicks this button, the dossier will go back to Path Modification Elaboration
      • Accept path modification offer: this is the ideal situation when Applicants accept the offer and the dossier will go back to Active Timetable with the updated timetable
      • Reject path modification offer: in this case, the dossier will also go back to Active Timetable, but without the changes, so the original timetable (before the Path Modification process) will remain


      Validity period has already started

      The following example will show the path modification process in the Ad-hoc Path Request process type. We follow the same use case as above.

      Once the path modification process has been initiated by the initiating applicant, the applicant’s timetable becomes editable and can request changes for the FUTURE DAYS by adding a NEW SUBPATH.

      The timetable is not editable when the dossier enters the path modification process because it contains days from the past, so a new subpath needs to create!



      Looks the same when the dossier entered the path modification process for the first time.

      Change timetable

      Changes were made, the timetable was shifted 2 minutes earlier in each Austrian station.


      We changed the timetable on the border section that should result in yellow lights on the partners' side:

      The next step is to define the running days in the calendar, the new subpath added with an empty calendar. The system indicates a warning message on the control.

      In the calendar, the past days and the future days are displayed differently.  

      If the path modification process started in the past for e.g. spending too much time with the harmonization then you need to adjust the validity period which will update it to today's date and restores back the passed days to the original path.

      In our example, the path modification process started one day earlier, the initiator Applicant decided to continue working and preparing the request on the next day (2020-09-05 which is today's date) .

      In the calendar, the 2020-09-04 has a faded green color to show that this day will not be part of the new request.


      The system indicates it with warning messages. In order to continue to submit the path modification needs to adjust the validity period for today's day.

      Please note that there will be no change for 2020-09-04, even though it was originally requested! The Adjust the validity period copies today's date as the start date, click Save. :

      After if the affected Applicant also accepted the request the initiator Applicant can submit path modification request.

      The process continues the same way as in the case of the validity period in the future. 

      Please read the path modification phase documents for further information.