Lean Opportunities for HUD Code Manufacturers
Executive Summary:
In collaboration with the Manufactured Housing Research Alliance (MHRA) and with funding from U.S. HUD and NYSERDA, researchers took the first steps in developing the lean production techniques that will shape the homebuilding factory of the future. Goals include: 1) increase design and production flexibility expanding the range and type of building solutions offered by modular and HUD-code home producers while cost effectively increasing production efficiency, 2) produce and install homes with zero defects, and 3) eliminate waste in all forms, including cycle times, building materials, and labor utilization.The second phase of our lean research efforts began in 2006. Nine industrialized housing plants (modular and HUD Code) were selected to begin the transition to lean production. Lean advocates from each plant participated in a 5 day intensive training session led by lean experts from Senco Products and UCF. The advocates then returned to their plants and began to lay the foundation for introducing lean. With the help of the lean experts, the lean advocates developed a plant level value stream map of their operation and used it to identify likely opportunities for improvement. These opportunities were prioritized and the top 3 areas were attacked using kaizen Rapid Productivity Improvement events (RPIs). The RPIs have resulted in significant reductions in waste and have also been instrumental in the developing a lean plant culture. More manufacturers have indicated an interest in the program and we plan to expand it in follow-up phases. Results from a typical RPI in an interior wall department include:
12% space reduction
10% wallboard damage reduction
Labor reduction from 9 to 6.5 people
$73,200 annual labor savings
Just as important were the "soft" benefits that were summarized in the following comments from industry participants:
“Taps into worker commitment to the company”
“We can make our workplace better”
“Morale in department very high”
“Wide range of RPI participants”
“Strong support of plant management”
“Spread lean company-wide”
“Workers understand production as a system”
“Forces company to confront critical issues”
“Provides forum for management to converse with workers”
As a result of these positive results, participating companies made the following long term commitments:
Corporate Lean Director
Full-time lean advocate at each plant
Lean training for plant associates
All plants will host continuing series of lean RPIs.
Technical Reports & Papers:
Manufactured Housing Research Alliance, Pilot Study: Applying Lean to Factory Homebuilding, U.S. Department of Housing and Urban Development, Office of Policy Development and Research, Washington, D.C., July 2007. [download report]Dentz, J. and Blanford, M., "Lean Factories Cut Costs, Boost Production", Automated Builder, July 2007.[download report]
Dentz, J., I. Nahmens, and M. Mullens, “Applying Lean Production in Factory Homebuilding”, Cityscape. 11(1)81-104, March 2009.[download paper]
Each plant presented their Phase II lean implementation results to national industrialized housing leaders at the Factory Building Symposium on Lean Production in Austin, Texas in January 2006. Each presentation and additional lean background material may be found on the MHRA lean website: http://www.research-alliance.org/pages/lp.htm
Plant presentations from the MHRA website may be viewed directly:
- Wall Production and Changeover Time - Hi-Tech Housing
- Clutter to Cash - Palm Harbor Homes (Abemarle, NC)
- Level the Load - Four Seasons Housing, Inc.
- Management Commitment - Southern Energy Homes
- Creating a Lean Infrastructure - Palm Harbor Homes (Plant City,FL)
- Building from Small to Large - Clayton Homes
- Building a Lean Culture - R-Anell Homes
- Leveraging Lean - Chelsea Modular Homes
- Empowering the Lean Team - Cavalier Homes, Inc.
More recent journal papers address wider implications of lean homebuilding:
Nahmens, I. and M. Mullens, “The Impact of Product Choice on Lean Homebuilding,” Construction Innovation: Information, Process and Management, 9(1)84-100, March 2009. [download paper]
The following journal paper explores two strategies for productivity improvement in industrialized homebuilding. The first strategy is extensive automation and the second is lean production. The paper concludes that extensive automation is a risky strategy for an industry subject to wild market swings and that lean production can provide many of the same benefitsMullens, M., " Innovation in the U.S. Industrialized Housing Industry: A Tale of Two Strategies," International Journal for Housing Science and Its Applications. 32(3)163-178, May 2008. [download paper]
