Fabrication-Driven Structural Optimization Techniques for Cost-Efficient Steel Construction Using CNC-Based Design Workflows

Abstract

This study investigated how fabrication-driven structural optimization improves cost efficiency in steel construction when delivered through CNC-based, BIM-enabled design workflows, addressing the problem that many “optimized” steel designs lose their economic advantage due to traceability gaps, revision churn, and incomplete fabrication constraint alignment across multi-tool, multi-organization pipelines. The purpose was to quantify the relationships among Fabrication-Driven Structural Optimization (FDSO), CNC Workflow Traceability and Data Integrity (CWTDI), Fabrication Constraint Compliance Index (FCCI), and Cost-Efficiency outcomes (CE) using a quantitative cross-sectional, case-based design. Data were collected from a purposive sample of 162 professionals embedded in enterprise steel delivery cases that used CNC fabrication and cloud or enterprise digital collaboration tools for model-to-detail-to-machine handoffs (structural engineers 24.1%, BIM/modeling 18.5%, detailers 21.0%, shop supervisors 16.7%, CNC/QA 9.3%, project managers 10.5%; mean experience 7.8 years, SD 4.6; 72.2% frequent CNC exposure). Reliability was strong (α: FDSO 0.88; CWTDI 0.90; FCCI 0.86; CE 0.89). Descriptively, respondents reported above-mid maturity (FDSO M 3.92, SD 0.62; CWTDI M 3.74, SD 0.71; FCCI M 0.77, SD 0.12; CE M 3.85, SD 0.66 on 1–5 scales). The analysis plan applied descriptive statistics, Pearson correlations, and multiple regression with controls (role, experience, project complexity). Headline findings showed strong positive associations with CE (FDSO r 0.63; CWTDI r 0.69; FCCI r 0.58; all p < .001) and a high explanatory regression model (F(6,155)=33.9, p<.001; R²=0.57; Adj R²=0.55) where CWTDI was the strongest predictor (β=0.41, p<.001), followed by FDSO (β=0.29, p<.001) and FCCI (β=0.18, p=.006; VIFs < 2.1). Case validation aligned higher traceability with fewer major revision cycles (2.1 vs 3.6) and fewer CNC regeneration events (1.4 vs 2.6), and cost-impact decomposition attributed perceived savings mainly to rework reduction (31%), then labor-hours reduction (24%), waste reduction (19%), coordination-cycle reduction (15%), and machine-time gains (11%). Implications suggest that organizations should prioritize digital-thread governance (release gates, revision propagation, audit trails) alongside fabrication-aware standardization to realize reliable cost efficiency from CNC-integrated optimization.