Here is an example of a queue that I have been part of as one of the buyers in queue at Starbucks today! One of their baristas told us — their valued customers in queue — that their system had to undergo a maintenance … at peak hour !
I guess there is good reason for it… more than what the barista was telling us. Sometimes, one has to ‘Stop the production line’ to make wrong things go right … regardless of the queue that builds up as a result.
This ‘Stop the work!’ applies to Lean-Agile as well… when key people are not executing at par as to what is expected of them in their role, then it is a problem… fix it… stop all work if need be.