A Service Design Principle to know when to fix something right away and when to make come back later.
If you can solve a customer or user issue in the next five minutes, do it with the person right away.
Are there tasks that you often delay in your service? Which tasks could you do right away to save time for the user and your staff?
It may lead to serious issues if not balanced with other principles, namely on time management, priority setting and task scheduling.
What are the dangers of tackling every task that comes along at once? Your focus for longer tasks is disrupted and important larger tasks are continually pushed to a later day.
So there's a strong counter-principle to the "2-minute rule": Keep your priorities straight. This could be as simple as old-school Eisenhower matrix or something more sophisticated Kanban board.
Some service providers - from your local watch shop to dentists, vaccine centers and fast food shops - actually have lanes or time slots specifically for walk-ins.
This allows for "batching" of small, transactional, low-focus tasks which is another time-tested organization principle for service workers. So block an hour every day for e-mail inquiries or, in this case, changing batteries.
All on the condition that you have enough work overall. If you're bored, you can always tackle according to the FIFO or FCFS principle: First In First Out / First come, first served.
I realize I'm not giving a good alternative to the stated principle, and my argument apply mostly for the provider, not the customer. And for customers, getting something done is fantastic. But you may end up favoring certain customers (small, somewhat urgent tasks) over others (longer tasks but also time-constrained).
I think it also neatly ties in with the "Let me know why others come before me" principle, so if a customer needs to wait for a small tasks to be completed, tell him it's going to take 25 min because there's prior tasks to be finished.
It's a welcome nuance that will many will benefit from as I'll link each principle to the community page with all comments to read additional stories and counter-arguments ;)
As you say, you can combine this idea well with other principles like "Let me know why others come before me" when you run a more complex service ;)
In the case of this small watch repair shop, they did it smartly. They ask the customer:
Does that answer your question?
The third draft of this Service Design Principle
Footnotes
Daniele’s notes