Queues are everywhere - at all levels - in the end a single transistor is either on or off - doing one thing at once. Your queue decouples demand from supply -

Queues are everywhere - at all levels - in the end a single transistor is either on or off - doing one thing at once. Your queue decouples demand from supply - though you now have another problem - if demand far exceeds supply will your queue overflow? In that scenario you might need to push the queue back to the requester - ie refuse the job and tell them to resubmit later.