A Lean-Based Approach to Streamline Production and Reduce Waste in Precast Concrete Panel Manufacturing

A Lean-Based Approach to Streamline Production and Reduce Waste in Precast Concrete Panel Manufacturing

2026

DOI: https://doi.org/10.60164/oyw5lwcd5

Authors: Alaa Abu Nokta, Mahdis Mazhari, Mahsa Honari Kalateh, Mohammad Darwish, Mohamed Al-Hussein, Ahmed Hammad, Farook Hamzeh

Citation:

Abu Nokta, A., Mazhari, M., Honari Kalateh, M., Darwish, M., Al-Hussein, M., Hammad, A., and Hamzeh, F. (2026). A Lean-Based Approach to Streamline Production and Reduce Waste in Precast Concrete Panel Manufacturing. Lean Construction Journal 2026 Special Issue CRC-CSCE pp 285-300 https://doi.org/10.60164/oyw5lwcd5 (Submitted 10Jan2026; Accepted 24Sep2026) www.leanconstructionjournal.org

Abstract:

Question: How can lean principles, including design standardization, waste elimination, and process optimization improve production efficiency and reduce material waste in precast concrete panel manufacturing?

Purpose: To analyze inefficiencies within a precast concrete panel facility and demonstrate how lean methods can streamline workflow, reduce waste, and enhance production reliability through design standardization, drawing optimization, and rebar-cutting optimization.

Research Method: A case study using direct observation, worker surveys, engineering team interviews, and root-cause analysis (5 Whys), followed by development and testing of lean-based countermeasures including standardized designs, simplified shop drawings, consolidated cutting lists, and a Python-based cutting-stock optimization tool.

Findings: Suggested Lean improvements reduced engineering time for shop drawings, minimized rework, eliminated multiple forms of Muda/Muri/Mura, improved communication on the shop floor, and significantly decreased Styrofoam and rebar waste through standardized designs and optimized cutting patterns. The combined rebar–plywood drawing lowered engineering effort by 40%, and consolidated material schedules improved production flow and removed bottlenecks in material preparation.

Limitations: Performance improvements were not measured on the long-term cycles.
Implications: Lean tools, particularly waste elimination and material cutting optimization, can meaningfully enhance off-site construction by improving workflow reliability, reducing design variability, and strengthening collaboration between engineering and production teams.

Value for practitioners: This study provides a practical lean framework that other precast or modular manufacturers can replicate to reduce design effort, improve clarity of shop drawings, eliminate waste, and increase production efficiency using both lean thinking and simple digital tools.

Keywords: Lean thinking, precast concrete, prefabricated panels, standardized design, production improvement, optimizing the process

Paper type: Case study