Sustainable optimisation framework for warehouse operator allocation

Warehousing faces increasing pressure to balance cost efficiency, sustainability, and workforce well-being. Existing studies often address these dimensions separately, leaving a gap in integrated decision-making. This study develops and validates a novel engineering sustainability framework that combines the Fuzzy Analytic Hierarchy Process (FAHP) with a multi-objective optimisation model to guide operator allocation under uncertainty. By prioritising Key Performance Indicators (KPIs) across economic, environmental, and social pillars, the framework translates sustainability trade-offs into actionable allocation strategies. A case study in a Tunisian hardware warehouse demonstrates that the approach reduces costs and energy consumption while improving operator safety and job satisfaction. Beyond warehousing, the framework illustrates how engineering methods can operationalise the triple bottom line to design resilient, cost-effective, and socially responsible industrial systems. The findings highlight both theoretical contributions by bridging FAHP and optimisation within sustainable engineering and practical implications for managers seeking to align efficiency with sustainability goals.