When I was driving down the highway in Vancouver with my girlfriend, I found a great example of flexibility. I got giddy with excitement and asked my girlfriend to take a picture for me. She laughed at me but then obliged. What I saw were lights that were part of their traffic system. It was a three lane road with no dividers. The lanes which you could drive in were illuminated with a green arrow. Being from LA and having to deal with the traffic on a daily basis, I thought this was a simple but brilliant system. Directional traffic volume changes on a continuous basis. In the morning, everyone might be headed north to get into the city but then in the afternoon, everyone heads south to get home. On a regular freeway, you have fixed resources - when demand changes, you can't adjust - leading to traffic. The ability to turn lanes to opposite directions allows the city to flex their capacity based on demand.
|The directional traffic indicators on a Vancouver bridge|
|Directional traffic indicators - Close up|
Here's an example from my factory. We have a mixed model value stream that builds three parts at high but erratic volumes. For the purposes of this example, we'll call them Items A, B, and C. A couple of years ago, someone thought it would be a good idea to create dedicated cells to all three items. Items A, B, and C all had dedicated operators and equipment. That was fine and dandy until the demand started varying. Let's say initially the demand was 2000 A, 2000 B and 1000 C. What do you think happened when the demand went to 500 A, 4000 B and 500 C? Exact same quantity but totally different mix. Well, the B operators and equipment had already been at their maximum and overtime could only get them so far. They had the free manpower and facilities from cells A and C but they weren't trained or equipped to build Bs.
Well "what did they do?" you might be wondering. The team created 3 ABC cells that could make all three of their runner parts. They duplicated all the tools required to make all three variants and also cross-trained all the personnel. Now when demand fluctuates, they are flexible enough to react to the variation... just like those Vancouver freeways.