Unknown Unknowns

Harvey Bernstein and Donna Laquidara-Carr of McGraw Hill Construction write about the growth of Lean, and lack thereof, in the February 17 issue of ENR.

A striking statistic:  "two-thirds (62%) of the fims using lean construction, or at least one of the lean practices measured in the survey, recognize that current, standard construction processes are inefficient.  In contrast, only 14% of the firms not practicing lean regard current construction processes to be inefficient."

Unkonwn unknowns, as Rumsfeld would say.

Trade contractors, it seems, suffer more from unknown unknowns:

55% of trade contractors report they are not familiar with any of the lean practices measured in the survey, compared with 38% of general contractors.  This 17-point gap is considerably larger than the 7-point gap between general contractors and trade firms that have adopted at least one lean practice.

But it's not because trade contractors are Luddites.  More of them use global positioning systems to track their materials, equipment and tools, more of them optimize crew sizes, more of them conduct studies of worker ergonomics and and activities, and more of them use preparatory tools and materials to train worker for specific tasks.

The study suggests that 80% of trade firms that do adopt lean practices see greater profits and reduced costs.