fire drill
1. An organized evacuation of a building to prepare its occupants for the proper procedure in the event of an actual fire. Less than an hour after the school day began, the students were ushered out onto the lawn for a fire drill.
2. By extension, any event, activity, or situation that is useless, unproductive, or a complete waste of time. Usually used in business. The massive flop of the company's newest smartphone means that the huge amount of time and money they invested in it ultimately proved to be nothing but a fire drill.
3. Any unexpected, hurried, and particularly chaotic task, activity, event, or situation. Usually used in business. The boss dropped a fire drill in my lap at the last minute, saying I needed to write up a 15-page report for the board by the end of the hour.