|Lean production is a business process originally developed by Toyota that strives to eliminate all kinds of waste (time, money, materials, etc.) from manufacturing, construction or office operations, while developing a culture that strives for continuous improvement. Lean processes have long been used in other industries, notably automotive, to improve quality while reducing the overall cost of production. Still, lean is relatively new to home building.|
The goal of lean production is to satisfy the customer by delivering the highest quality at the lowest cost in the shortest time, using less of everything. This is accomplished by continually eliminating waste in all forms: defects, overproduction, transportation, waiting, inventory, motion and processing. Originating with the Toyota Production System, lean production is the result of decades of development by automobile manufacturers, who have reduced average labor hours per vehicle by more than half, with one-third the defects. Other industries have followed the automobile industry's lead, achieving similar results. SBRA's ongoing work suggests similar opportunities for housing manufacturers.
This project investigated the application of techniques from lean production to the sales and installation process of factory built homes with the goal of proving that these techniques have the potential to dramatically reduce waste and improve housing quality, including energy efficiency. Lean techniques were implemented in partnership with Titan Homes, a producer of modular and manufactured homes in Sangerfield, NY, and a select group of their dealer customers. In partnership with these companies, researchers conducted value stream mapping exercises, lean training workshops and three rapid process improvement (RPI) efforts. The RPIs focused on the sales process, ship-loose materials configurations and installation efficiency improvements. Researchers conclude that there is great potential for using lean techniques to improve these processes; however, significant barriers exist to successful implementation. This report suggests strategies for overcoming these barriers and applying the lessons learned through this effort to other companies in the state, including factory and site builders.
The following figure shows the current state value stream map for a typical home installation. Each step in the process is shown as a box containing data about that step including crew size, lead time and cycle time. Dashed lines with arrowheads represent information flow. Solid lines represent the flow of materials. Value stream maps are used to help identify and illustrate waste in a process.