Recently the TSA instituted a trial process of allowing people to self-select the security line using as a way to speed up the security process.  The test has resulted in a moderate improvement in throughput and is a great application of the power of visual management, a concept core to lean manufacturing.  Though not the same scenario, it did remind me of the time when I was a member of my churches Board of Trustees and decided to apply some lean manufacturing techniques to speed up communion. 

The old method of taking communion was chaotic with parishioners filing into the center aisle regardless of their location in the church. It was simply the fastest to the aisle would dictate the order of communion. Often people in the back would thrust forward cutting off people in the front aisles. This in turn caused a traffic jam of parishioners yielding long communion times and frustration.  

Realizing the problem we instituted a process that controlled the flow of parishioners to the aisle in the spirit of one piece flow.  We simply placed ushers in the aisle with the direction that they only allow the front row pew to proceed into the aisle for communion first. Just as the first row of pews would finish entering the aisle the second row of pews would be allowed to enter and so on. In doing so we were able to control the rate into the aisle based on the tact of the priest providing communion. This in turn eliminated the traffic jam and cut the communion time in half with significantly fewer complaints and chaos.   Over time as the parishioners became accustomed to the new process, we required fewer ushers to control the flow.