How to represent a time duration feature for cases where time is still counting
I have a problem where I am trying to classify the outcome of costumer complaint cases. I have several features already such as type of item bought, reason for complaint etc...
I am trying to add a feature that represents how long a case is 'open' (meaning waiting for resolution). The logic being that a case that is 'open' for long is unlikely to have a positive outcome.
Issue is, I am traning my model on 'closed' cases, hence have a set closing date. When I apply this model in production it will be for 'open' cases, which have no set closing date.
The most logical thing to do is to calculate de closing date as: duration = OPENING_DATE - Now()
But this seems like It will lead the model into assuming the case will close at the present moment which is most likely not the case.
Is there a better way of feature engineer this?
Thank you