• 86% of trade firms optimize crew sizes, compared with 80% of general contractors.

• 40% of trade firms conduct studies of worker ergonomics and activities, compared with just 33% of general contractors.

• 37% of trade firms use preparatory tools and materials to train workers for specific tasks compared with 30% of general contractors.

This suggests that even though fewer trade contractors are currently adopting formal lean philosophies or formalized practices, a strong percentage of them are seeking ways to improve the efficiency of their approaches to construction, which makes them strong candidates for lean adoption.

While all firms that participated in the survey were asked whether they use these approaches to increase efficiency, only those that have adopted at least one of the lean practices were asked about their plans to use these practices in the next three years. Trade firms report wider expected use of preparatory tools and methods to train workers for specific tasks (88% versus 62%) and use of studies on worker ergonomics and activities (68% versus 41%) than general contractors do.

Benefits of Lean

Most firms that use at least one lean practice report achieving several important benefits from it. Roughly the same percentage of general and trade contractors report achieving key benefits like greater customer satisfaction and shorter project schedules.

However, for several key benefits indicated in the chart on the next page, a higher percentage of lean practitioners in the trades are reporting a medium to high level of achievement.

Perhaps the most important factors are also the ones with the greatest differential between general and trade contractors: greater profitability and reduced cost. This benefit is particularly important because, among the contracting firms that have heard of lean but have not adopted any of the lean practices measured, the highest percentage (83%) said this benefit would be highly influential in their decision to adopt lean if it could be proven to be a benefit. Clearly, knowledge that a high percentage (80%) of the trade firms that use lean practices see greater profits and reduced costs would be compelling to firms that might consider adopting these practices.

These findings are also reflected in the belief by the trade contractors using lean that the benefits of lean accrue directly to their bottom line, not just in their ability to bid projects more successfully.

The research conducted in the "Lean Construction SmartMarket Report" included qualitative, in-depth interviews with advanced lean practitioners. A few of the trade contractors that participated in these interviews provide a more nuanced view of the impact of lean on their bottom line.

One expert stated, "Our margins have improved to expectation, so instead of taking a job at 4% or 5%, and being lucky to get 3%, we are taking the job at 4% to 5% and we're making 4% or 5%." Another noted that reliability of outcome is an enormous benefit, with reliability changing from 20% to about 80% on projects. Clearly, this direct business benefit makes a compelling case for the adoption of lean principles by trade firms.

Trades’ Influence on Lean