The pandemic related economic slowdown is impacting building projects in a variety of ways. Reports from projects across the United States include delays related to manpower shortages and additional physical distancing measures to complete shutdowns due to state or local mandates. Project starts have been delayed, by as much as six months, given present uncertainties.
I am hearing that many project leaders are starting to discuss how they can make up for lost time. Some of the strategies they are considering are similar to those employed in the past to recover delayed projects. They are listed here along with my perspective on each from a lean culture and practice perspective.
Adding a Second Shift: In the current environment this approach is considered as a means of increasing physical distancing as well as accelerating planned work. The principal challenge with the approach is loss of productivity. University of Wisconsin researchers developed a formula for calculating the productivity loss¹. For a project splitting work equally between the two shifts the expected productivity loss is 17%. Even shifting 20% of the work to a second shift yields a productivity loss of 10%. People working second shifts are also subject to mental and physical fatigue, especially for those not acclimated to evening work.
Scheduling Overtime Work: Overtime capacity is a strategy Toyota employs, so might be interpreted as a lean practice. Toyota uses this capacity as a buffer against workflow variation to meet daily production targets. Overtime judiciously used as a short-term buffer can be effective, however used as ongoing practice has significant costs. Costs and risks include increased cardiovascular conditions, relationship problems, injury and a reduction in productivity.²
Increasing the Size of Crews: Staffing crews above an optimum level results in a reduction in productivity equal to about 4% for every 20% increase in crew size.³ The strategy also complicates physical distancing measures that projects will have in place, and in a tight labor market may not even be possible.
Planning Continuous Workflow in Small Increments: A continuous workflow approach divides work into distinct areas, and sizes crews so operations progress at a standard pace through the project. Within each area there is only the people, materials and equipment associated with the operation in progress. This clear demarcation of work areas facilitates a physical distancing strategy. The smaller the area, the more quickly the project progresses without increasing the hours worked or crew size. Normally there is increased productivity due to decreased interference between crews. An effective small increment, continuous flow strategy can decrease the time required for construction by 30% or more.
While it is the last approach listed above, the lean approach of planning continuous workflow in small increments is proven to accelerate schedules while reducing costs and should be the first approach you consider.
Best wishes for your health and safety!
(1) Impact of Shift Work on Labor Productivity for Labor Intensive Contractor, Awad S. Hanna, Ph.D., P.E., M.ASCE; Chul-Ki Chang, Ph.D.; Kenneth T. Sullivan, Ph.D.; and Jeffery A. Lackney, Ph.D., https://ascelibrary.org/doi/abs/10.1061/%28ASCE%290733-9364%282008%29134%3A3%28197%29.