Lean construction is a translation and adaption of lean manufacturing principles and practices to the end-to-end design and construction process. Unlike manufacturing, construction is a project based-production process. Lean construction is concerned with the holistic pursuit of concurrent and continuous improvements in all dimensions of the built and natural environment: design, construction, maintenance, salvaging, and recycling. Source: http://en.wikipedia.org/wiki/Lean_Construction
BIM also attemps to coordinate workflow and crews, eliminate rework, encourage more off-site prefabrication, and keep project stakeholders aware of changes on the construction site. The combination of BIM tools (like flowline scheduling and production control) and Lean processes can be quite rewarding.
We're getting ready for the 18th annual Lean Construction Conference in Haifa, and expect that these lean processes will be discussed in great detail:
Business Plan Validation - Target Value Design
More and more Owners are starting to realize that the traditional Design Bid Build process has a lot of waste in it and does not lend itself to a smooth, collaborative project delivery. In order to facilitate an integrated project delivery sophisticated owners developed a new contract type called the Relational Contract. Under relational contracts, the owner bears the ultimate risk for the project's financial and performance goals. This risk may be mitigated, to the extent that a guaranteed maximum price has been established, a profit participation agreement is reached or a possible recovery against participants for negligence or breach of their contracts is pursued. The participants also risk a variable portion of their compensation, such as a bonus opportunity or innovation fund in order to stay incentivized for on time under budget delivery.
The AIA recently published a guide about IPD. For more information about the guide go to: http://www.aia.org/ipdg
Lean Production Control (Last Planner System)
The Last Planner SystemTM (LPS) is a lean production-based project planning and management process. It's a process that based on series of conversations between the project manager and the subcontractors. It provides a framework for each conversation (weekly work plans, 6 week look ahead schedule) and helps the PM in capturing and monitoring commitments from subcontractors. LPS aims to change the culture of project management, and therefore requires coaching and consulting to get through the implementation processes. It focuses on the people and the process aspect of construction.
A good summary of the methods and techniques that Last Planner uses can be found here: http://www.cif.org/Nom2003/Nom17_03.pdf
Vico Control is the logical next step for anyone who implements pull scheduling. Last Planner provides a framework for the discussions and culture change that implementation of Vico Control requires. Russell Kenley's (professor of Construction, Unitec New Zealand) paper about Control and Lean describes how Control can help reduce the complexity of the construction process. You can read more here: http://www.projectflow.com.au/papers.asp.
Caption: In this flowline chart from Vico Control, it is very easy to see the schedule inefficiencies. The blue circles indicate gaps in the schedule; the red circles indicate crew clashes in a particular location -- called interference. Understanding these issues ahead of time makes it easier for the superintendent to problem-solve with the subs.
Subcontractors Adopting Lean
There are several subcontractors that have implemented Lean tools and concepts. One of the most interesting is Ipurity. Ipurity is a specialty piping company that was created as a Lean company from the ground up. The CEO of the company has more than 20 years of experience in Six Sigma, Lean and supply chain management. They created a subscription based model for installing clean piping systems for high-tech and bio-pharma customers. The subscription model allows for a high level of transparency between them and their clients. It also allows them to standardize and optimize their processes at a very high level. This in return reduces the cost of their services while maximizing profit margins.
Subcontractors involved the SSM St. Clare project were selected very early in the design process. They closely collaborated with the design team, and built a BIM model of the project. This enabled them to prefabricate most of the Mechanical and Plumbing systems. This process eliminated costly field work and allowed the subcontractor to maximize work in the shop. Approximately 75% of the HVAC piping, 80% of the ductwork and 65% or plumbing systems were prefabricated.
Summary
There are many different Lean tools available for forward thinking project teams and companies. Lean concepts are tools that project teams should evaluate based on projects, contracts and people. Process change requires commitment and vision from the people taking part in the effort. Technology, such as Vico Control, combined with other Lean concepts can expedite adoption of a more efficient construction process.
Learn more about the combination of Last Planner and Vico Control:
Blog: Scheduling with Lean Techniques (Part 1)
Blog: Scheduling (and Controlling) with Lean Construction Princples (Part 2)
Product: Vico Control homepage
Webinar: BIM 401: Model-Based Scheduling
Webinar: 4D Scheduling Strategies in a Hard Bid
The paper, The Combination of Last Planner and Location-Based Management System, co-authored with Glenn Ballard, explores the best practices for scheduling and controlling commercial construction projects, and will be presented this Summer at the 18th Annual Conference for the International Group for Lean Construction in Haifa.