When the HealthSystemChangeParameters event is called/scheduled to update the behaviour of the bed-days allocations, it does not change the behaviour of the bed-days allocations in the HealthSystem.

The HealthSystemChangeParameters event which changes the availability of bed days currently changes the BedDays.availability property when it runs:

• The BedDays.availability value is only used by the BedDays class in set_scaled_capacity
• set_scaled_capacity itself is only used in the initialise_beddays_tracker method.
• initialise_beddays_tracker is only called once in the initial setup of the simulation (specifically in the initialise_simulation step for each module).

As such, changing the BedDays.availability property when an event fires after the simulation begins has no effect.

If we really only need to set the properties of the BedDays tracker before the simulation, we don't need an event to handle changing them. Otherwise, presumably the correct action that should be taken is that the availability property should be updated, and the internal trackers for maximum capacities should also be updated? This might lead to issues with the current and forecast allocations though (since EG setting the availability to 0 will mean that any currently scheduled occupancies have to end).

If anyone knows what the intended behaviour is meant to be (or whether we need this feature at all), advice would be appreciated!