Improving Energy Efficiency through Bottleneck Analysis in Food Manufacturing: A Theory of Constraints Approach

Abstract

The manufacturing industry faces increasing challenges in achieving both operational efficiency and environmental sustainability. In the food sector, high energy consumption during production processes makes energy efficiency a critical concern. This study applies the Theory of Constraints (TOC) to identify production bottlenecks and evaluate their implications for energy efficiency within the framework of green manufacturing. Using a case study approach, data were collected through observation, interviews, and production performance analysis. The TOC five-step methodology was implemented to identify, exploit, subordinate, elevate, and continuously improve constraints. Findings reveal that the main bottlenecks occurred in energy-intensive stages, particularly cooling and packaging, which recorded the longest cycle times of 21.6 s/unit and 24.1 s/unit, with utilization rates above 90%. Addressing these bottlenecks led to an 18.9% increase in throughput (from 148 to 176 units/hour), a 13.9% reduction in energy consumption (from 1,255 to 1,080 kWh/shift), and an improvement of the energy efficiency index from 74.6% to 84.2%. Idle time was also reduced by 45.8%, indicating smoother production flow. The study concludes that integrating TOC with green manufacturing provides a systematic and practical approach for improving both sustainability and competitiveness in the food industry.