The structure of OTAS is determined by transitions from one stage or phase of the surgical process to another. It only considers the process of multidisciplinary teamwork on the day of an operation
| Phase | Stage | ||
|---|---|---|---|
| 1 | 2 | 3 | |
| 1: Preop | Preop planning and preparation | Patient sent for anaesthesia | Patient setup to operation readiness |
| 2: Intra-op | Opening/access to contact of target organ | Operation specific procedure | From preparation to close to closure complete |
| 3: Postop | Anaesthetic reversal to exit | Recovery and transfer | Feedback: selfassessment |