Helping to simplify and correct the sentences of quality management system

Please help to simplify and correct the sentences of quality management system below.

As the project quality management system of my company has been approved to ISO 9001, I have to under compliance with the system of ISO 9001 standard requirements. This entailed formalizing the organizational structures, documenting the operational procedures and keeping records of all the construction activities including contract documents, incoming & outgoing correspondence, drawings, purchase orders, testing & commissioning form, handover inspection form.

To achieve the certification to ISO9001, both internal and external audits were required. Therefore, I had to ensure that all the documents, records, and drawings were properly registered, signed, delivered, documented and followed up if necessary.