LEAN Construction Alert: "Defining Constraint"
“Constraint” is a key term in Lean. It is the identification of impediments to accomplishing tasks for the purpose of removing those impediments. In a recent AGC webinar hosted by the AGC, "Lean From A Specialty Contractors' Perspective" (July 17, 2012), TDIndustries spoke as the specialty contractor and commented that some of its customers objected to using the word “constraints” and so, for those customers, TDIndustries substituted the phrase “make ready.”
This comment, made almost as an aside, crystallizes the clash between Lean processes and the processes encouraged by traditional contracts. Customers do not want to hear about “constraints” because that signals a contractor is going to make excuses for not performing its contract obligations and/or request more time, money or resources. Customers do not want to allow more time, money or resources, so current contracts are written to suppress identification of constraints. Contracts impose rigid deadlines for giving notice of “constraints” and often require burdensome documentation. Contractors do not want to fuss with the paperwork of notice and do not want to look like a “complainer,” so the constraints are often ignored until the cost of dealing with the constraint is so high it cannot be ignored.
In Lean, identifying a constraint does not signal a party wants to “excuse” its performance. To the contrary, it is fundamental to achieving performance. A contract should encourage removing impediments, not create them.