LTP and STP Processes: Difference between revisions

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A train schedule is identified by a UID.  Each UID may apply to several versions of a schedule, and each version may apply on different days - for example, if the train runs to a slightly different calling pattern on Saturdays and Sundays.
A train schedule is identified by a UID.  These identify a group of schedules within a CIF file.


A version of a schedule can be uniquely identified by the schedule UID, start date and STP indicator field.  If multiple schedules exist for a given date, the one with the lowest STP indicator is the valid one.  This composite primary key is used when processing schedule updates to select the correct record to revise or delete.
= Planning Process =


= STP Indicator =
The industry has two planning processes: Long Term Planning, and Short Term Planning.


The Short-Term Planning (STP) indicator for a particular schedule indicates the type of schedule:
== LTP Process ==
 
As far out as D-67 (or 67 weeks before the day the train runs), the LTP timetable starts to be planned.  At D-26, Network Rail issue the new LTP timetable electronically - this results in several thousand additional schedules being produced per day.  Changes may still occur after D-26, and will usually be variation requests to cope with engineering work or altered train operations.
 
== STP Process ==
 
The STP process begins at TW-30 (or 30 weeks before the train runs), and is targeted to be complete by TW-12, the deadline for the Informed Traveller timetable.
 
= Schedule data =
 
Schedules have one of four value in the STP Indicator field:


{| class='wikitable'
{| class='wikitable'
! Indicator
! Name
! Name
! STP Indicator
! Abbreviation
! Abbreviation
! Description
! Description
|-
|-
| Permanent
| P
| P
| Permanent (LTP)
| WTT
| WTT
| A schedule which was generated by the Long-Term Planning process
| A base schedule created as part of the LTP process
|-
|-
| Overlay
| O
| O
| Overlay (LTP)
| VAR
| VAR
| A variation to a schedule generated by the Long-Term Planning process
| A variation to a schedule created as part of the LTP process
|-
| Short-Term Planned
| N
| STP
| A schedule which was generated by the Short-Term Planning process.  These are usually 'one-off' trains.
|-
|-
| Cancellation
| C
| C
| Cancellation (LTP)
| CAN
| CAN
| A planned cancellation which overlays the WTT schedule.  This effectively says 'the schedule does not apply today', and are not an operational cancellation.  See [[Planned Cancellations]].
| A planned cancellation of an LTP schedule - this means the schedules does not apply, not that it is cancelled - see [[Planned Cancellations]]
|-
|-
| N
| Short-Term Planned (STP)
| STP
| A schedule created as part of the STP process
|}
|}


'''NOTE:''' A ''CAN'' schedule will have no locations in the schedule, and exists to indicate that the train will not run on this date - it is a planned cancellation.  This is a separate type of cancellation from an operational cancellation, where the train was planned to run, but was later cancelled.
LTP schedule UIDs should contain one or more records with indicator 'P', and zero or more with indicators 'O' or 'C'.  STP schedule UIDs should contain one or more records with indicator 'N'.  There are some circumstances where a UID may contain both LTP and STP records - this can be down to an STP schedule being converted in to an LTP schedule in the next timetable period.
 
= Validity =
 
A UID will refer to either:


* One or more WTT schedules and zero or more VAR or CAN schedules, or
== Determining which schedule applies ==
* One or more STP schedules


It is not possible for a UID containing a WTT schedule to also contain an STP schedule.
Where there is more than one schedule with a UID valid on a particular day - such as when a WTT schedule is overlaid by a VAR or CAN schedule, the 'O' or 'C' schedule takes priority over the 'P' schedule.  A maximum of one overlay should apply on any one particular day.


Where more than one schedule appears to be valid for a particular date (for example, where a WTT schedule is overlaid by a VAR or CAN schedule), the schedule that is valid is the one which has the lowest alphabetic STP indicator.
An easy way to calculate this programatically is to look for all schedules under the selected UID, whose validity covers the date in question.  If there is one schedule, this is the schedule that applies.  If there are two schedules, the schedule with the 'O' or 'C' indicator is the one that applies.


Let's look at an example for UID A12345. There are two schedules:
Let's look at an example for UID A12345. There are two schedules:


* WTT schedule valid on Monday, Tuesday, Wednesday, Thursday and Friday from Monday 7th January 2013 to Friday 11th January 2013
* WTT schedule valid on Monday, Tuesday, Wednesday, Thursday and Friday from Monday 7th January 2013 to Friday 11th January 2013
Line 58: Line 62:
* The CAN schedule is valid on Wednesday 9th and Thursday 10th January 2013
* The CAN schedule is valid on Wednesday 9th and Thursday 10th January 2013


If retrieving all the schedules for UID A12345 on Wednesday 9th January 2013, we'll see two schedules - the WTT schedule and the CAN schedule. Picking the schedule with the lower alphabetical STP indicator will select the CAN schedule, which is the schedule that applies on the day.
If retrieving all the schedules for UID A12345 on Wednesday 9th January 2013, we'll see two schedules - the WTT schedule and the CAN schedule. Picking the schedule with the lower alphabetical STP indicator will select the CAN schedule, which is the schedule that applies on the day.


{{Navtable-DataFeeds}}
{{Navtable-DataFeeds}}


[[Category:Schedule Data]]
[[Category:Schedule Data]]

Latest revision as of 16:17, 18 March 2019

A train schedule is identified by a UID. These identify a group of schedules within a CIF file.

Planning Process

The industry has two planning processes: Long Term Planning, and Short Term Planning.

LTP Process

As far out as D-67 (or 67 weeks before the day the train runs), the LTP timetable starts to be planned. At D-26, Network Rail issue the new LTP timetable electronically - this results in several thousand additional schedules being produced per day. Changes may still occur after D-26, and will usually be variation requests to cope with engineering work or altered train operations.

STP Process

The STP process begins at TW-30 (or 30 weeks before the train runs), and is targeted to be complete by TW-12, the deadline for the Informed Traveller timetable.

Schedule data

Schedules have one of four value in the STP Indicator field:

Indicator Name Abbreviation Description
P Permanent (LTP) WTT A base schedule created as part of the LTP process
O Overlay (LTP) VAR A variation to a schedule created as part of the LTP process
C Cancellation (LTP) CAN A planned cancellation of an LTP schedule - this means the schedules does not apply, not that it is cancelled - see Planned Cancellations
N Short-Term Planned (STP) STP A schedule created as part of the STP process

LTP schedule UIDs should contain one or more records with indicator 'P', and zero or more with indicators 'O' or 'C'. STP schedule UIDs should contain one or more records with indicator 'N'. There are some circumstances where a UID may contain both LTP and STP records - this can be down to an STP schedule being converted in to an LTP schedule in the next timetable period.

Determining which schedule applies

Where there is more than one schedule with a UID valid on a particular day - such as when a WTT schedule is overlaid by a VAR or CAN schedule, the 'O' or 'C' schedule takes priority over the 'P' schedule. A maximum of one overlay should apply on any one particular day.

An easy way to calculate this programatically is to look for all schedules under the selected UID, whose validity covers the date in question. If there is one schedule, this is the schedule that applies. If there are two schedules, the schedule with the 'O' or 'C' indicator is the one that applies.

Let's look at an example for UID A12345. There are two schedules:

  • WTT schedule valid on Monday, Tuesday, Wednesday, Thursday and Friday from Monday 7th January 2013 to Friday 11th January 2013
  • CAN schedule valid on Wednesday and Thursday from Wednesday 9th January 2013 to Thursday 10th January 2013

The result of overlaying these two schedules is that:

  • The WTT schedule is valid on Monday 7th, Tuesday 8th and and Friday 11th January 2013
  • The CAN schedule is valid on Wednesday 9th and Thursday 10th January 2013

If retrieving all the schedules for UID A12345 on Wednesday 9th January 2013, we'll see two schedules - the WTT schedule and the CAN schedule. Picking the schedule with the lower alphabetical STP indicator will select the CAN schedule, which is the schedule that applies on the day.


Network Rail Open Data Feeds
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Train Movements Train Movements Feed Train Activation Train Cancellation Train Movement Train Reinstatement Change of Origin Change of Identity Change of Location TSPEED Field Planned Cancellations Cancellation Codes
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