- I know that PNPSCADA can allocate portions of a meter’s consumption to an individual Meter Account (i.e. a tenant pays for a portion of the common area). If a tenant vacates the property, is it possible that the allocations are automatically recalculated (because the common property consumption is now spread over less tenants) or do all allocation portions have to be changed manually for all the remaining Meter Accounts (i.e. tenants)? How do you normally deal with this situation?
- Can the above be changed in hindsight at any date of the month, i.e. if the tenant vacates the property on the 14[SUP]th[/SUP] of that month, can the billing system accommodate the new allocation portions from that date, or would it happen in the new billing period?

The answers are yes, and yes.
Regarding the first query:
For you to do this, you'd typically enter the Area of each tenant, and calculate the portion of each tenant in proportion to how much area the shop covers. To enable this, you need go to "Edit->Meter Account" and check the "Calculate Portion according to Premise's Area" check box, as well as fill in the Area of Premise (m2) (if you want to measure this according to a different unit, click on the 'm2', and enter the new unit).
You need to do this for ALL the meter accounts looking at a particular meter. In that case, the portions will be automatically calculated at Meter Account Edit time.
When one tenant then moves out, you can tick the "Meter Account disabled (e.g. if Premise is vacant/unused)" check box on the same screen, which will cause the portions on all the other Meter Accounts to be recalculated, not taking the vacated premise into account.
Regarding the second query, the plot thickens:
Basically, if you want to stick to your billing periods, and make sure a tenant that moved out and a new tenant that moved in somewhere in the middle of the month are only charged for the portions that they should pay, there is a way to do this, but this involves splitting the meter at the time of move out, by going to the relevant Meter Details, and clicking on the 'tenant move out' link. What this will do, is end off the meter at that date, and start a new meter of the same serial number at the same time. It goes to the Meter Accounts and makes sure all the Meter Accounts now contains a summation of both meters: the old (disabled) one, and the new active one. The old meter's profile history will stop the moment the new meter's profile history begins. On your Profile Graph, this would typically display as an unbroken graph.
You have to then have a new Meter Account for the new tenant, and the old Meter Account for the old tenant. Remove the new meter from the old Meter Account, and if you have a new tenant, remove the old meter from the new tenant's Meter Account.
What this will accomplish, is that the other tenants' meter accounts will now also contain the two meters. If there is no new meter account yet, what this effectively will mean is that the portion for the new meter will be higher for the other tenants, and for the old meter will be smaller, since the old tenant was still in place at that time.
In this way, the billing system can accurately accommodate the different allocated portions both before and after that date, on the same bill.
Please make sure the meter has been read in up to date before you split it, since the old meter will not be read in again. And make sure your Meter Accounts reference the correct meters.
Note:
If you also do the second option of splitting the meter, you won't use the "Meter Account disabled (e.g. if Premise is vacant/unused)" check box, since the portion recalculation already happens. The "Meter Account disabled (e.g. if Premise is vacant/unused)" check box is only useful if you re-use your Meter Accounts for new tenants, and want to leave the Meter Account for a certain shop 'vacant' for a complete billing period.
So, yes, you have a bit of an option here as to how you want to use PNPSCADA, which depends in a way on your external business processes: does your Meter Account entity stay with the shop, or with the tenant-per-shop (in other words do you create a new Account Number for a new tenant, or do you re-use the old Account Number for a new tenant in the same shop).