Zero-incident goals in high-risk areas like car factories require construction contractor safety management. The Contractor Safety Management System (CSMS) will assess contractor performance and determine the relationship between contractor categorization and safety outcomes. Mixed-methods analysis included gap analysis, chi-square tests of independence, and linear regression. The survey included 119 contractors (A: major, B: medium, C: minor). Safety patrol data and CSMS audit ratings for each clause were independent variables (X), whereas contractor categorization was dependent (Y). Plan (15.97%), Do (15.27%), Check (11.76%), and Act (18.49%) show considerable disparities between present and ideal CSMS performance, with Class A contractors performing better. Safety patrol results showed a 25% link and 42% mutual influence with the contractor class. However, CSMS clause-based survey responses did not statistically affect contractor classification (100%). The study found an association between contractor size and observed safety procedures (patrol findings), although formal CSMS audit clauses cannot distinguish between classes. It appears that contractor safety performance needs improvement and that the present CSMS evaluation system may need to be revised. Construction contractors must manage safety to achieve zero-incident goals in high-risk locations like car factories. This study uses the Contractor Safety Management System (CSMS) to detect gaps and determine the relationship between contractor categorization and safety outcomes.

Mixed-methods analysis included gap analysis, chi-square tests of independence, and linear regression. One hundred nineteen contractors; A (big), B (middle), and C (minor)—were studied. Safety patrol data and CSMS audit ratings for each clause were independent variables (X), whereas contractor categorization was dependent (Y). Class A contractors performed better in all Plan-Do-Check-Act (PDCA) phases: Plan (15.97%), Do (15.27%), Check (11.76%), and Act (18.49%). Statistics revealed a 25% link (and 42% mutual influence) between contractor classification and safety patrol findings. Conversely, CSMS clause-based survey responses did not significantly affect contractor classification (100%). Patrol findings show a correlation between contractor size and visible safety measures, although formal CSMS audit criteria cannot distinguish performance between classes. Due to this gap, contractor safety performance needs to be improved, and the present CSMS evaluation system may need to be refined to better forecast and improve safety outcomes, supporting zero-accident KPIs. Predict and improve safety results to support zero-accident KPIs.