Nobody's perfect, and a management system does not work like a clock from the first day.
Reality in the field does not always match the plans. If you find, for example through the monitoring and measurement described above, a nonconformance (something that does not work properly, for example, a deviance from target values), you will have to act. Such responses to problems that have already happened are corrective actions. They are the key to continual improvement of your environmental management system.
Corrective actions are complemented by preventive actions, i.e. actions taken in order to prevent potential nonconformances from happening at all.
