OSHMS element priorities

When establishing an occupational safety and health management system (OSHMS), there are certain mandatory elements, as stipulated by the OSH Act of Trinidad and Tobago (2004) as amended. However, based on wider exposure to safety management, a concern arises that these mandatory elements do not add up to a comprehensive and complete OSHMS. From a review of international legislation, standards, codes, and guidelines, key OSHMS elements may be grouped as follows: (1) mandatory (based on local legislation), and (2) essential (based on international standards). What hierarchical structure emerges from this prioritisation exercise?