Are there any apps which can generate a series of tasks based on a decision and obviously automated ? I will set activities which need to be done by static person at a stable proximity of the event. The thing that will change is the kind of event.

As example For event type ‘Small Event’,  I always need the following to happen:
– 3 weeks before the event, person A must create something.
– 2 weeks before the event, person B must do something.

there will be more complicated task list, but be sure you have understand the idea. I need to generate the task list by automatic upon the type of event it is.
Does anyone know of anything that can help?