Batch & Queue Construction?

Have you ever been in line at a sandwich shop where the "sandwich artist" was making three sandwiches at a time?  You know, he pulls out three loafs of bread, puts the meat & cheese on all three sandwiches, wraps each of them in deli paper, and hands all three to the clerk at the cash register.  It's happened to me, and I was not amused.  Why?  Because I was first in line out of the three, and I had to wait three times as long to get my sandwich.  Not only that, but I had mine toasted and it was darn near cold by the time I sat down to eat it!  Okay, I'm a little demanding of my eateries, but I can't help it; I'm a lean geek.

What does this have to do with Lean?  It's all about batch-and-queue vs. one-piece flow (click here for a good explanation from the Shmula blog).

The Case for One-Piece Flow

In the lean manufacturing world, the debate on batch-and-queue production vs. one-piece flow production has long since ended (batch-and-queue lost).  Anybody who has studied the Toyota Production System understands the superiority of one-piece flow: reduced inventory, early detection of defects, reduced transportation, more scheduling flexibility, and (most importantly) an increased organizational awareness of the need to solve problems preventively due to the lack of buffers in a single-piece flow.

So, where do we stand with respect to these principles in the construction industry?

Batch & Queue Construction

I've had a difficult time explaining my thoughts on this.  My belief is that in the construction industry, we typically exhibit the traits of a classic batch-and-queue operation, even though we're not technically batching buildings together.  Here are some of the similarities:

1. Work is done by specialized groups (concrete finishers, framers, drywallers, plumbers, electricians, etc.) dedicated to performing a narrow scope of work
2. These specialized groups try to optimize their own operations, even if that means a delay in the completion of a building
   
3. Item #2 above means huge amounts of time are spent waiting for the product to transition from one specialized phase to the next
4. Because of the delays between specialized work phases, the cause & effect trail of defects can go cold, resulting in fewer problems getting solved at the root cause
   
5. There is little collaboration between specialized groups, resulting in less innovation

Hey, lean geeks, does this sound familiar at all?

Lean Construction

So, what is the lean approach to construction?  What could be done to move from a batch & queue approach to a one-piece flow approach?  Do the construction folks think it's even necessary to make this transition in order to achieve operational excellence? Your thoughts?  I certainly don't have all the answers, but here are a few pie-in-the-sky ideas:

1. Create multi-functional work groups, consisting of highly-skilled installers capable of performing a wide range of installations
2. Equip your highly-skilled installers with all the equipment (possibly custom-built equipment) necessary to complete a wide range of installations
3. Utilize visual management to encourage participation through shared information
4. Pre-fab as much as you can inside factories on lean assembly lines

I'm sure that experts like Dr. Michael Mullens with the Housing Constructability Lab or Hal Macomber at Reforming Project Management have a lot more to say about this subject than me, but those are my wild fantasies.  Are they feasible?  Your thoughts?