Using Lean Principles to Optimize the Delivery Process of Façade Engineering
Question: How can Lean Construction principles, and Value Stream Mapping (VSM) in particular, be applied to visualize and improve the façade engineering delivery process? Purpose: The purpose of this study is to develop and apply current-state and future-state Value Stream Maps to the façade engineering delivery process to identify sources of workflow inefficiency and propose Lean-based improvements. Research Method: The study applies a Design Science Research approach to a representative façade engineering case, combining semi-structured interviews with 15 international façade experts and a systematic literature review to define process phases and consultant–contractor interfaces, and develop current and future-state VSMs. Findings: The current-state VSM reveals significant inefficiencies related to fragmented communication, late contractor involvement, design rework, approval delays, and information handoff discontinuities. The future-state VSM demonstrates that early contractor involvement and digital collaboration platforms can substantially reduce workflow fragmentation and non-value-added activities, with expert informed estimates indicating up to a 60% reduction in non-value-added time. Limitations: The VSM was developed using a generic façade case and expert judgment rather than project-specific quantitative data; therefore, the results indicate potential improvements requiring empirical validation. Implications: The study demonstrates that Lean principles and VSM can be effectively adapted to engineering intensive, iterative delivery processes, extending their application beyond traditional linear construction workflows. Value for practitioners: The proposed VSM framework enables façade stakeholders to visualize workflows, diagnose delays and rework, and improve coordination, predictability, and delivery performance. Keywords: Lean Construction, Value Stream Mapping, façade engineering, workflow variability, early contractor involvement, process optimization. Paper type: Full paper