Thru internal audit all the processes and system are reviewed with reference to the criteria defined by the company. The criteria for the audit could be ISO 9001(QMS) ISO 1400 (EMS), OHSAS 1800 (SMS) etc. Audits can also be done with reference to internal procedures and policies of the management/company.
Internal Audits ensures that all the rules are followed diligently by all personnel. The duration of Internal audits usually are two times year. This ensures that all the employees do their work effectively, consciously and cautiously. Having an internal audit is a good method to make sure all employees work is done regularly and properly as per the standard.