Pick up any construction trade publication or attend an industry trade show and you’ll inevitably encounter discussions about lean construction. Almost 30 years after the concept was introduced, lean construction remains one of the most talked about topics in the industry.

Perhaps your company has eagerly embraced the concept and is one of its leading advocates—or maybe you’re one of the many industry executives still struggling to make sense of all the competing theories, confusing terminology, and specialized systems and tools.

Regardless of where you stand—whether you’re on board and eager to enhance your capabilities or still trying to sort through the jargon—it’s important to have a grasp of some basic lean construction principles.

The Goal: A More Predictable Project
In one sense, the lack of clarity about lean construction is ironic considering that the topic has been talked about since the early 1990s. That’s when manufacturing companies such as Toyota began advocating new production and management systems designed to cut costs, increase throughput, and improve quality.

Organizations such as the International Group for Lean Construction (IGLC) and the Lean Construction Institute (LCI) soon started trying to apply these same techniques in the construction industry. Broader industry groups, such as the Associated General Contractors of America and the Construction Management Association of America, also took on the challenge.

Unlike mass production, however, most construction projects are customized, one-off projects, which makes them inherently less predictable. Making construction processes more predictable proved to be a difficult hurdle.

While many industries have become dramatically more efficient since the 1990s, the LCI reports that construction labor efficiency and productivity have actually decreased to the point where 70 percent of today’s projects go over budget or are delivered late.

Competing Visions: What They Have in Common
Dozens of competing practitioners, consultants, and software providers now offer various lean construction visions and frameworks. One group offers a five-step approach, while others promote six principles of lean. Some proponents focus on removing seven types of waste from the construction process; others target eight categories of waste. Various academic researchers have weighed in with their views too, but there is still not a single, universally accepted definition of the term, “lean construction.”

Despite their many variations, however, most lean construction approaches share certain basic goals. Chief among these is eliminating waste or non-value-added activities. The LCI, for its part, organizes these concepts into six broad principles:

1. Optimize the Whole. Look beyond local efforts or individual trades, and instead study the overall outcome to determine where value is added or waste exists.

2. Generate Value. Examine every expenditure of resources to determine if it is actually generating value, as defined and communicated by the customer.

3. Remove Waste. Waste is defined as any effort or use of resources that does not create value. Waste is not always obvious, and it takes effort to identify and minimize it.

4. Focus on Process and Flow. Standardizing processes and leveling the workflow helps minimize variations, thus enabling more consistent output and predictable results.

5. Support Continuous Improvement. Create an environment where experimentation is encouraged and small, manageable failure is acceptable. This can drive innovation that will benefit the entire value stream.

6. Respect People. It is people who transform plans and materials into useful value. Respecting the contribution of each individual is essential.

Lean Tools and Techniques
The tools used to implement lean construction also vary widely. In addition to those devoted specifically to lean construction, such as the LCI’s Last Planner System, other tools and systems also can support or drive the lean effort—either directly or indirectly. These include integrated product delivery systems, value stream mapping, and building information modeling (BIM) software, among others.

Like everything else related to lean construction, it is impossible to say in advance which of the various tools or systems would be best suited for your company—or even if lean construction is right for your projects. It can take considerable research to find out, but the promised benefits—reduced waste, lower costs, improved safety, faster timelines, and more predictable projects—could make the effort worthwhile.