Conceptualising a Value Stream Mapping (VSM) - based decision - making model for lean energy retrofitting of HVAC systems in high-rise buildings: literature review approach

Abstract

The built environment sector accounts for a considerable global energy consumption, making energy retrofitting a critical strategy for enhancing energy efficiency while reducing operational costs. However, conventional energy retrofitting exhibits several limitations often caused by fragmented interventions and limited long-term impacts. Previous studies across different industries demonstrated that the lean concept is capable of optimising processes while maximising the value. Hence, it is worth to explore on how to integrate lean concepts in energy retrofitting to optimise energy consumption and energy costs. As the initial step, this study aims to investigate the value stream mapping (VSM) as a decision-making approach for lean energy retrofitting through a non-systematic review approach. The collected data were analysed using thematic analysis technique. The findings reveal that the incorporation of the lean concept in energy retrofitting enables various advantages. Further, VSM, one of the key lean tools, can be identified as a promising solution for energy retrofitting that enables facilities managers to visualise energy flows and identify non-value adding items. Secondary data evidence indicates that VSM-guided interventions can yield significant reductions in both energy consumption and project lead times compared to conventional methods. Accordingly, this study proposed a conceptual VSM-based decision-making model for lean energy retrofitting in HVAC systems in high-rise buildings as the key outcome of this research. Overall, the study identified that lean-integrated energy retrofitting facilitates a more adaptive, resource-efficient, and sustainable approach for energy retrofitting than the conventional method.