Tier 1 is a short questionnaire used as a first check for people moving into jobs involving exposure to vibration. The replies to the questionnaire will indicate whether they need to be referred to Tier 3 for a HAVS health assessment.
Tier 5 involves referral of the employee for certain tests for HAVS. The results may help the doctor assess fitness for work.
Adoption of this approach may help you keep costs down and avoid long term absences.