In your risk assessment, consider how often it should be reviewed and comment as such- different risks different timescales. By generating high, medium or low risk ratings, consider with each a timescale between reviews. Include timescales for reporting actions on findings, (maybe monthly). If using equipment, you would make sure it is safe & working correctly prior to use and that you have PPE etc. Similar process for buildings and occupancies. Baldyman has quoted Article 9 which is fine but still does not dictate. Making a judgement call is the assessors business. Sorry, that is not exactly helpful. I would base 1,3 & 5 years inspection points , subject to any changes as above for buildings and take consideration of occupancy & processes and adjust timescales with notes of evidence.