Testing sequence

Dear All,
Is there any specific sequence in which the particle count, HEPA filter leak test, airflow velocity, airflow visualization tests are carried out?

Better you can follow the sequence defined in ISO 14644-3.
Why because, if you measure the particle count without testing the filter integrity, you cannot make a concrete conclusion.
And, if you conduct the recovery test without calculating the number of air changes per hour, it may give abnormal results