Bringing Predictability to the Construction Process

Editor's Commentary

The construction process is a lot like an intricate puzzle ' all the pieces need to fit together properly to ensure timely, on-budget project completion.

Because of its complexity, the Lean Construction Institute (LCI), a non-profit research organization, is seeking to help contractors streamline this process. LCI is inspired by the lean revolution used in manufacturing. 'Our aim is to develop and apply principles drawn from that revolution to the design, management and improvement of project-based production systems,' says Gregory Howell, LCI co-founder.

At first, the principles of lean construction may be hard to swallow. 'Current practice focuses on optimizing each task. So people make assignments to keep their labor utilization high,' notes Howell. 'That, oddly enough, is likely to reduce project success.'

He emphasizes, 'We're not opposed to optimized labor utilization. But if you make work flow more predictable, you actually get it done faster and for less money.' According to LCI research, even on well-run projects, planning by foremen is able to predict only about 50% of the tasks that will be completed within one week's time. 'That means that the next crew is either waiting for work to be available or ready, or stands idle because the following crew doesn't know which tasks will be completed next week,' Howell points out.

The inability to anticipate when work will be ready can add costs. 'It might be that the people in the field are doing the work in each one of their activities to maximize their productivity, but are not causing predictable work release from one crew to the next,' says Howell. 'So the cost and schedule reports can look really good, but the flow of work in the field is almost chaotic.'

The first goal of lean construction is to instill predictability into this process. 'You start by reforming your planning system so you can create a predictable work flow,' says Howell. 'That means you have to come to grips with some serious deficiencies to traditional project management. For example, current project management would say you're under control if you're meeting cost and schedule targets. We'd say you're under control if you can do what you say you're going to do next week.'

Classic project management applies a command and control ' the schedule tells you what to do and when. By contrast, 'planning is promising' in lean construction. 'Working back from each milestone, the people responsible for the work build a schedule as a series of requests (to perform work) and promises to hand off work meeting specific criteria,' explains Howell. 'In turn, weekly and daily tasks are only released for work when all constraints are removed and the performance of the planning system is measured by comparing promised and actual completions.'

The results of this process can be dramatic. According to Paul Reiser, vice president of production and innovation at Boldt Construction, Appleton, WI, their best lean projects are typically characterized by a 20% schedule improvement, significant cost savings and 'highly satisfied customers.' Companies have also seen substantial reductions in accident rates, Howell adds. To learn more, visit the LCI web site at