Using Type Ids
Choose this option when you have set up Type IDs and you wish to create arrival patterns for an origin that take different service types into account, along with the order in which they arrive. Arrival Profiles that have the same Type ID will be allocated the same arrival times on import. The first step of this procedure describes how to create Type IDs for an Arrival Profile.
To create frequency based data:
- To associate an Arrival Profile with a particular type of train or service (express or stopping service, for example), enter a name or letter next to the profile in the corresponding cell labelled ‘Type ID’ (the example illustrated below uses an ID for express trains: ‘T1’, and one for stopping services: ‘T2’).
- Select Use from the drop-down list labelled ‘Use/Ignore type IDs’.
- Time intervals are automatically copied when the 'Frequency Based' option is set to 'Yes', based on a table's Arrival Profiles (Origin Settings sheet) or Services (Platform-Train Settings sheet).
- From the drop-down list labelled ‘Apply service type sequence?’, select Yes or No. If you choose No, go to step 8.
- From the drop-down list labelled ‘Sequence: Continuous or Per Interval’ choose Continuous or Per Interval. If you choose ‘Continuous’, go to step 7.
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Having chosen ‘Per Interval’, enter either:
the sequence of Type IDs you wish to apply to all time intervals (enter them into the cell labelled ‘All’; for example, enter T1,T2).
or
the sequence of Type IDs you require in the appropriate cells along the timeline, for example T1,T2 in the first interval, T1,T1,T2 in the next interval, and so on.
Using the examples in step 1, this means that a sequence of ‘Express, Stopping Service’ will occur in these time intervals, starting from the beginning in each new interval. Now go to step 8.
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Having chosen ‘Continuous’, enter the sequence of Type IDs you
require in the cell labelled ‘Continuous sequence (Type ID)’, for example,
T1,T2
Using the examples mentioned in Splitting an Origin into Suborigins , this means that a sequence of ‘Express, Stopping Service’ will recur continuously throughout the model’s runtime.
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To specify the frequency of arrivals (across the whole simulation
or within individual time intervals), enter either:
A value for ‘Arrival frequency (per period)’ to specify the number of arrivals within each time interval (enter this in the first cell marked ‘All’)
or
Enter a number of arrivals per individual interval in the appropriate cells along the timeline.
Notice that the spreadsheet won’t allow you to both: inappropriate data will appear as light grey. You can remedy this by deleting the data you don’t need.
- To set the minimum time between arrivals:
- If you want arrival times to be randomised within the constraints of the time period, select Yes from the drop-down list labelled ‘Random arrival?’
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To add random noise to the numbers of Entities in your Arrival
Profile, enter ‘Minimum’ and ‘Maximum’ values in the appropriate cells.
As an example, if you set minimum and maximum limits of 2 and 5, a cell containing an initial quantity ‘10’ will ultimately be modified to contain between 5 & 8 (if noise is subtracted) and between 12 and 15 (if noise is added). The demand total is preserved regardless of noise.
- To spread the arrival of Entities over a certain period, add a value (in seconds) to the cell labelled ‘Spread arrivals (sec)’. This ensures that Entities don’t all arrive in one instantaneous surge, which may be unrealistic.
This portion of the worksheet should now resemble this screen shot.
After import, these setting will create the same six Arrival Profiles mentioned in Splitting an Origin into Suborigins . However, the data for the suborigins (the train cars) will be divided into two groups of six arrival ‘spikes’. This is due to the sequence ‘T1,T2’ and the ‘Arrival frequency’ of ‘12’ per period (in this case the period is the whole runtime of one hour). This graph illustrates these spikes after import.