It encourages companies to assess their own SMS against set key performance indicators (KPIs) and provides a minimum expectation (level 1) and three further levels of increasing best practice guidance, which a company may wish to apply in their SMS to improve ship management safety performance. Through self assessment, companies are encouraged to use ship management assessment results to develop phased improvement plans that can be applied across their entire fleet and to share their OVMSA self assessments with potential charterers using the OVMSA database.