To ensure continuous improvement and building up of history.
In essence the complete quality management system has been created and implemented at levels 1 to 3. At level 4 the system needs to run for a certain period:
- To prove that it really is a cycle
- To build up history, e.g. build up files with records such as complaints, notifications and improvement suggestions, revision and optimization of documents, internal audit reports and action plans. This serves to learn and improve the system.
- In addition, all methods and equipment will have to be validated at this phase.