The University of California San Francisco (UCSF) has been using Lean construction methods since 2007 to effect improvements such as consistent on-time delivery; avoidance of claims and costly adjudication; competitive, predictable costs; and improved design and building performance. The approach works by applying Lean management principles and concepts to the design and delivery of capital projects. First employed on private-sector projects such as industrial plants and hospitals, these ideas have started to show their value in the design and delivery of complex projects for the public sector over the last decade. Examples include the State of Washington, the Massachusetts College of Art and Design, and the U.S. Army Corps of Engineers.
Lean construction identifies what is valuable in a construction project and studies existing work processes to remove waste. Six Lean principles guide the modifications:
Identify value from the point of view of the customer.
Understand the streams of work by which value is delivered.
Achieve a smooth flow within work processes as waste is removed.
Employ pull planning (1) so that nothing is made or delivered until it is needed.
Make continuous efforts to improve existing processes.
Develop and use applied technology to improve access to and use of information.
Lean design and construction differs profoundly from traditional approaches to project management. (2) What distinguishes Lean is that it takes a scientific approach to product and process improvement--one that tries to constantly improve on the recipe. The essential feature of Lean is that the production environment is much more closely coupled with the pre-production. Also, the independence of the production environment is nurtured by making it easier to solve problems as they arise downstream.
Traditional project management strategies attempt to optimize the project by:
* Isolating activities and optimizing each one, assuming that customer value (3) has been defined in the design phase (which takes place prior to the construction phase, and is minimally informed by construction phase participants).
* Breaking the project into logical, sequenced components and estimating the time and resources for each activity.
* Developing a separate contract for each component, wherein it is individually monitored against schedule and budget projections.
With traditional project management, if specific activities or sequences of activities run into problems or fall behind, efforts are made to isolate the problems, often by trading cost for schedule. To the extent that problems cannot be addressed successfully within this framework, disputes and litigation often arise.
For example, on a traditionally managed cogeneration plant construction project, a delay in procuring steam turbines will likely delay the delivery and installation of those turbines as well as the overall commissioning of the cogeneration plant. There is a domino effect; if one component encounters roadblocks, the entire project suffers. If Lean tools like pull planning scheduling and just-in-time procurement had been used instead, the additional cost and time could have been wholly avoided.
Focusing on the Big Picture. The Lean approach to design and construction addresses both the design of the project and the processes by which the project will be realized, identifying the customer's objectives for the project and eliminating each element of the process that does not add value. Design and construction are understood and organized as a single, intertwined, continuous flow of work. The project team seeks to perfect the overall process and create a reliable production flow across the entire process, rather than isolating individual activities and focusing on the productivity characteristics of each element of work. In other words, the idea is to optimize performance at the project level, not on an individual, component-by-component basis.
One fundamental lesson of Lean production management is that process components cannot be managed individually. Each component affects other components; they are...