Empirical Study of Identifying Logistical Problems in Prefabricated Interior Wall Panel Construction

Off-site prefabrication is becoming widespread in the construction industry owing to quality, safety, and schedule benefits, but logistical costs are still among the largest barriers to adopting it. This study focuses on stacking plans, which encapsulate information on logistical processes, for prefabricated interior wall panels to identify logistical problems and their potential solutions. Due to the scarcity of reports on logistical problems in the construction industry, the authors studied operations research and defined two metrics, stability and reshuffling effort. From two case projects, the authors found that the stability and reshuffling effort of stacks were 47% and 44% on average, respectively, where it is desirable to achieve high stability and low reshuffling effort. The authors also identified three causes of the problems associated with unstable stacks and reshuffling effort: (1) inherent difficulty avoiding unstable stacks and reshuffling effort simultaneously due to the panel designs and their installation sequences; (2) ad hoc adjustments of priority between stack stability and reshuffling effort; and (3) incapability of consistently creating stacking plans on a Pareto optimal surface. Interviews showed that the problem related to unstable stacks and reshuffling effort and their causes are commonly found in construction projects that use prefabricated interior wall panels. To address these problems, one of the potential solutions identified is to develop a methodology to generate stacking plans on a Pareto optimal surface considering stack stability and reshuffling effort.