Learning to identify and eliminate waste through the utilization of lean strategies can dramatically affect this ratio and provide maximum value to clients and end-users.

Lean is an operating strategy that emphasizes flow efficiency over resource efficiency. Lean construction professionals possess the tools to influence a safer and more productive workforce while eliminating waste and enhancing quality and value.

But what if you went even further than leaning the jobsite equation, and evaluated how lean construction methods affect efficiencies in the off-site manufacturing environment?

Let’s look at DOWNTIME, an acronym for identifying the eight major wastes prevalent in the construction industry, to evaluate how these deadly wastes can be mitigated through the lens of modular construction.


With less risk to weather exposure and damage to materials, workmanship and quality are enhanced in a controlled environment, meaning that efforts caused by rework, scrap and incorrect information are lessened. Quality control and assurance are enhanced using technology, standardized designs, repeatability, and the focused skillset of workers based on the task. Combined with proactive controls and inspections for each work activity, deficiencies are greatly reduced.


We can eliminate extra steps and make work safer in the off-site environment. Modified activities can remove the need or duration of lifts, ladders, or fall protection as we take work from heights on-site, to ground level in the plant. Due to the repetitive nature of tasks in a controlled environment, it is much easier to study workflow and continually make improvements by identifying and removing non-value-added steps, motions and other waste.


Wasted time waiting for the next step in the process can lead to overproduction on another task. The off-site environment promotes the ability to complete work in parallel with other tasks. Benefits include the ability to work in inclement weather, which enhances schedule compression, and can mean early revenue generation for the client as they aren’t waiting for the product.


The key to employment of the DOWNTIME approach in the off-site environment involves taking full account of the team’s talents and skills at each level – including students, new hires and senior staff. The promotion of knowledge transfer and mentoring between the workforce of the future and our legacy staff ensures that new technology and fresh ideas combine with the knowledge and experience provided through legacy mentoring. Through standardized designs, tasks can be matched with specific skillsets to maximize our most important resource, our people.


Construction sites receive fewer parts and pieces when employing off-site construction, which means less material movement. Less activity on-site has a positive impact on the surrounding environment, including fewer requirements for parking, lower embodied energy rates and carbon reduction, which also result in less cost.


Traditional approaches can mean large amounts of products and materials being stored and processed on-site. The off-site perspective means less congestion, more availability for critical materials, and less material movement on-site. The controlled environment lends itself to better utilization of space, organization of materials and segregation of waste, as well as a stronger sense of pride in keeping things tidy when workers return to the same space each day. While creating accurate builds, BIM modeling also enables more precise material procurement with standardized details and designs, thus minimizing excess inventory of raw materials.


The production line mentality reduces worker and material movement by approximately 50%, which promotes less wear and tear on the body, promoting longevity of careers. Work completed in a controlled environment is inherently safer. Activities can be modified to prevent unnecessary movements and promote ergonomically focused work behaviors. This lessened risk equals a decrease in exposure hours.


Producing more outputs than are required before they are truly needed, or out of sequence, can lead to other forms of waste and prevent efficient flow on the job site. Working on items that are not yet required can lead to waste of waiting in the form of delays, additional meetings, additional resources and overtime. Also, the work that was truly needed and not getting done now needs to be rectified. Work completed out of sequence can also cause extra work for the next trade, if it interferes with their scope of work.

Parallel work at an off-site facility does not create these wastes. The use of pull planning in combination with a just-in-time delivery approach from the off-site facility can be employed for sequencing critical steps of work, and creating more controlled project timelines with minimal waste. Excess production can be avoided in the plant by manufacturing multiple projects at the same time, which enables flexibility in work activities to balance workflow and resource utilization.

Paul Frolick is a Process Improvement Leader at PCL Constructors Canada Inc..