Revise and update the model regularly

Outdated models can also originate model risk. Once implemented and accepted, a
model should not be considered as a finished manufactured good, but should be
revised and updated on a regular basis. Would you buy risk management software if
the vendor does not update it regularly? So why not do this as well with your models?
A related issue is the update of input parameters: the environment is changing.
Therefore, the input parameters should be revised and updated as frequently as
necessary.
Here again, a good signal is the acceptance of a model in the marketplace. If the
majority of the market uses similar data inputs and assumptions for comparable
activities, this is a good signal that the model is still up to date.