Use of the enhanced model is advisable if the system should be used to track other safety measures, such as radiation protection, safety in the workplace and fire protection, in addition to lockout/tagout.

The architecture of the enhanced model is as follows:

• A work approval can be assigned to several orders. However, an order can only ever be assigned to one work approval. (assignment rule R3)

• An application can be assigned to several work approvals, and vice-versa. (assignment rule R4)
• A work approval can only be assigned to one application of an application type. For example, it is not possible for several work clearance applications to be assigned to one work approval. (assignment rule R5)
• A work clearance application can be assigned to several operational work clearance documents, and vice-versa. (assignment rule R2)