While reactive, crisis management would respond to a crisis that was (typically) prepared for in advance, to the extent possible. It's highly scenario-based. Not all situations can be foreseen or planned for ahead of time. However, certain situations can be responded to via a documented playbook as a guide (i.e., what happens in the event of a natural disaster?). Management by crisis is a highly reactive management style where events are prioritized based on their occurrence and not based on strategy. Think of 'putting out fires' in an organization instead of working through an established plan. If you are familiar with the whack-a-mole game, managing by crisis is very similar.
While reactive, crisis management would respond to a crisis that was (typically) prepared for in advance, to the extent possible. It's highly scenario-based. Not all situations can be foreseen or planned for ahead of time. However, certain situations can be responded to via a documented playbook as a guide (i.e., what happens in the event of a natural disaster?).
Conversely, management by crisis is a highly reactive management style where events are prioritized based on their occurrence and not based on strategy. Think of 'putting out fires' in an organization instead of working through an established plan. If you are familiar with the whack-a-mole game, managing by crisis is very similar.