Screening Effectiveness of Mandatory Self-Assessment in Korea’s Steel Structure Fabrication Plant Certification: A Five-Year Analysis of Score Differences and Decision Discrepancies

Korea’s steel structure fabrication plant certification system requires applicants to submit a self-assessment form before certification assessment. This study evaluated the screening effectiveness of this mandatory self-assessment and its potential for procedural simplification. All 42 new certification assessments conducted from 2021 to 2025 were analyzed across 11 assessment categories and 56 assessment subitems. The agreement and magnitude of paired subitem score differences were summarized descriptively, and discrepancies in pass/fail decisions were evaluated using an exact McNemar test. Of 2352 paired subitem scores, 2071 (88.1%) were identical. Among the 281 differing scores, 213 (75.8%) were lower in the certification assessment, and the median absolute score difference was 2.5 points. Although all 42 applications satisfied the minimum scores in self-assessment, 12 (28.6%) failed the certification assessment (p < 0.001). The self-assessment form accounts for 7 of 18 required application pages; removing it would reduce the documentation to 11 pages, a 38.9% reduction. These findings indicate limited screening effectiveness of mandatory self-assessment for identifying applications that subsequently fail certification assessment and support considering simplification of the required self-scoring form while retaining documentary evidence and certification assessment.