The structure of ISO 45001 from OHSAS 18001 was one of the biggest changes. ISO 45001 is now based on the same high level structure as other management systems, such as quality (ISO 9001: 2015) and environment (ISO 14001: 2015).
Annex L is a new management system format that helps streamline the creation of new standards. As a result of it being used across multiple standards, it makes implementing a number of standards within a single organization easier. Annex L replaces ISO Guide 83. Guide 83 originally was a base structure and standardized text for management system standards. This structure was not common across the multiple standards making it difficult for organizations to implement multiple standards.
