What is path variant



It describes the path variants and introduces the behaviour of the comparison of path variants in some use cases.



Path variant is a timetable combination of all existing sub-paths with a consistent calendar. The path variants view gives you an overview of variants of the running days for each generated(calculated) variant. 

Basically, the "splitting" is done according to the calendar. In a complex path request, can still be difficult to keep an overview of the complete traffic business related to one specific capacity request/allocation.

See a simple example where a simple applicant's request can become more "complicated" as a result of the IM's response, as the offer contains multiple subpaths, and how it would look in the path variant view:




The comparison view was based on the calendar the user can compare to each other the applicant's request and the received IMs'offer. 



The comparison button is located on the Path variant view:


The system presents the order of timetable combinations according to starting running day according to the reference point in their first territory.


Click the calendar icon to access the calendar view.

Calendar comparison colour description:

  • The blue colour means the days were requested
  • The red colour means days requested but not offered
  • The green colour means days not requested but offered
  • Show with common running days’ which means that requested or offered path variants sharing at least one common running day will be compared one against the other. In the drop-down menu of listed path variants, those path variants that do not have common running days will be inactive. All active path variants will be displayed.


The comparison algorithm works in such a way that the reference timetable is always on the left, so it is worth considering which timetable we want to compare with because the display of colours will change and have different meanings.

In the same example that showed in the screenshot above, the path variant view shows the common days in blue and the removed days are red if the applicant timetable is compared with the IM timetable when the applicant timetable is selected as the reference timetable.

Days in red are shown as removed because IM has offered fewer days for the same subpath in the calendar view:

But if the IM timetable is compared with the applicant timetable and the IM timetable is the reference timetable then the previously "removed days" will be "offered days" because the IM is created two more subpaths.



PCS shows warning messages on the path variant view if the applied changes have an impact on the timetable combinations

  • Inconsistent borders
  • Could not define appropriate alternative origin/destination
  • It shows the subpath that cannot be connected to any timetable combination


Use cases

1# Alternative destination/origin

Once the subpath is marked as an alternative origin/destination in the timetable, it will be shown on the path variant view.  The existing path variant (*T1S1 - **T2S1) will be dissolved by creating a new subpath and assigning days to path variants ( T1S1)  that are removed from the existing path variant. The created path variant cannot be connected to any timetable combination it becomes a user variant.


2#  - Negative border time (If all times entered at the border)

If the arrival time at the territory 1 border location is before the departure time at the territory 2 border location, PCS considers the path construction possible. Therefore, path variants may be constructed with negative border times (departure from the next territory takes place one day later) which is not always wished by the applicant in the applicant timetable. 



This negative border indication works in the Create New Dossier Wizard (CNDW). The negative border time indication is visible on the Control and it will be visible for the involved agencies where the negative border time exists



3# - Negative border time (if entered the next territory)

If the subpath in the next territory has an earlier departure time at the border than the previous territory, in this use case the path variants cannot be constructed because path variants cannot cover all territories.



4# - IM offer is later than the Applicants' request

If the applicant’s request for the path is close to midnight (e.g. Tuesday 23.55) while an IM sends an offer after midnight (e.g. Wednesday 00.05)  the time difference could be only 10 minutes but the path comparison view shows inconsistency and path variants cannot cover all territories. 

* T 1S1 = territory 1 subpath 1

** T2S1 = territory 2 subpath1