The safety and health plan for construction works: preventive planning tool or mere formal compliance

The construction sector is characterized by high organizational complexity derived from its temporary, dynamic, and process-specific nature. This industry registers some of the highest occupational accident rates worldwide. Within the European regulatory framework, Directive 92/57/EEC establishes the Health and Safety Plan (H&SP) as the principal instrument for preventive management on-site. In Spain, the transposition of this Directive introduced a preliminary design-phase document (Health and Safety Study or Basic Study, H&SS/H&SBS), intended to identify risks and define preventive measures that subsequently inform the contractor’s H&SP. Despite the importance of H&SS/H&SBS documents within the safety management process, empirical evidence remains limited regarding both their technical quality and their predictive capacity to explain the quality of subsequent H&SPs. This study addresses this gap through a qualitative and quantitative approach aimed at evaluating the intrinsic quality of H&SS/H&SBS and H&SP documents and modelling the dependency relationship between them. A database comprising 560 documents (280 H&SS/H&SBS and 280 H&SP) from 280 construction projects was assessed using a Delphi-based expert evaluation tool combined with a ratio weighting method. The results reveal consistently low levels of document quality and a limited capacity of H&SS/H&SBS to predict the quality of the corresponding H&SP. These findings suggest a systemic “cascade” failure in preventive planning, whereby documents frequently operate as instruments of formal compliance rather than as effective safety management tools. Our models’ findings support the need for effective audits and advanced technical training for professionals drafting these documents to improve preventive planning.