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Proceedings / IGLC 34

IGLC 34 · Singapore, Singapore · 2026

Digital optimization for green construction – reducing rebar waste and carbon emission

  1. Junior Expert, Strategic Project Management Department, PT Wijaya Karya (Persero) Tbk., Jakarta, Indonesia, yura.mr@wikamail.id, orcid.org/0009-0004-8184-2003
  2. Expert 1, Strategic Project Management Department, PT Wijaya Karya (Persero) Tbk., Jakarta, Indonesia, akbar.ashari@wikamail.id, orcid.org/0009-0009-4036-8313
  3. Junior Expert, Strategic Project Management Department, PT Wijaya Karya (Persero) Tbk., Jakarta, Indonesia, adi.permadi@wikamail.id, orcid.org/0009-0009-6921-5046
  4. Junior Expert, Strategic Project Management Department, PT Wijaya Karya (Persero) Tbk., Jakarta, Indonesia, bayu.ap@wikamail.id, orcid.org/0009-0001-7605-0579
  5. Expert 1, Strategic Project Management Department, PT Wijaya Karya (Persero) Tbk., Jakarta, Indonesia, aminullah@wikamail.id, orcid.org/0009-0008-1031-1570
  6. Expert 2, Strategic Project Management Department, PT Wijaya Karya (Persero) Tbk., Jakarta, Indonesia, anang.wirdianto@wikamail.id, orcid.org/0009-0004-9007-4747

https://doi.org/10.24928/2026/0169

Abstract

Reinforcing bar (rebar) is a major cost component and contributor to embodied carbon in reinforced concrete construction. In practice, rebar must be cut from standard stock lengths, and inefficient cutting plans often lead to material waste and disruptions in production flow. This study investigates how digital optimization of rebar cutting plans can reduce waste and support planning processes in construction projects. A case study approach was applied using QCDSMPE and quantified Ishikawa analysis to identify root causes, followed by the development and implementation of a digital optimization system across three pilot projects. The results show 2.4% reduction in rebar waste, corresponding to significant cost savings and an estimated reduction of 132,535 kgCO₂e. In addition, preparation time for cutting plans decreased from 3.7 hours to approximately 1s hour per Bar Bending Schedule (BBS). The findings demonstrate that digital optimization of material planning can improve resource efficiency, support workflow reliability, and contribute to both economic and environmental performance in construction.

Keywords

  • Lean construction
  • Last Planner System
  • production flow
  • rebar cutting plan optimization
  • embodied carbon.

Cite this paper

APA 7th edition

Rizaldi, Y. M., Ashari, A., Permadi, A., Putro, B. A., Thalib, A., & Wirdianto, A. (2026). Digital optimization for green construction – reducing rebar waste and carbon emission. In F. Hamzeh, M. Poshdar, N. P. Garcia-Lopez, & V. Gan (Eds.), Proceedings of the 34th Annual Conference of the International Group for Lean Construction (IGLC 34) (pp. 461–472). https://doi.org/10.24928/2026/0169

Shortened reference for IGLC papers

Rizaldi, Y. M., Ashari, A., Permadi, A., Putro, B. A., Thalib, A., & Wirdianto, A. (2026). Digital optimization for green construction – reducing rebar waste and carbon emission. IGLC34. https://doi.org/10.24928/2026/0169