Workload leveling based on work space zoning for takt planning

This paper focuses on a location-based method used in construction, namely the Work Density Method (WDM) for takt planning. The contribution to knowledge is presenting a problem formulation and a mathematical optimization algorithm to divide a work space into zones while leveling work densities across trades in a process. Given a work space and the number of zones in which to divide that space, the so-called WoLZo problem is to identify the shape and dimensions of each zone while minimizing the peak in the trades' workloads per zone. Increasing the number of zones tends to result in lowering the peak, but application of the WoLZo algorithm shows that this trend levels out due to the spatial distribution of work densities. Application to work density maps of different granularity sheds light on zoning work spaces and sharpens one's intuition on how many zones to select. These findings inform data collection pertaining to work density as needed when planning construction work on the basis of takt. •Develop the body of knowledge of takt planning of construction projects•Define workload leveling and zoning, a problem to solve when takting a process•Offer a novel mathematical formulation and algorithm to address this NP-hard problem•Present results and trade-offs between number of zones, workload peak, and takt•Compare current practices of zoning with the results from the WoLZo algorithm