AS Per ISO 9001:2008, Quality of a Project is the responsibility of 1 Quality Manager 2 QA/QC Engr. 3 Project Manager 4 Site Engr. 5 Everybody

The Quality of any project is the responsibility of everybody working in this project, directly or in-directly.

For quality everbody working in that project is responsible.

QA is critical than QC as QA has responsibility to control the defects in future. QA has a role of defining the quality policy and how to follow the policies in better way do that there wont be any issues/defects to customer

For Quality maintaining :5 Everybody is responsible.

Iso9001:2008 is a Quality Management concept begins and go through all stages consistently improving the qualities at all levels by fixing  and defining the job and the responsibility at all levels of the organisation.

ISO9001:2008 specifies requirements for a quality management system where an organization

1. needs to demonstrate its ability to consistently provide product that meets customer and applicable statutory and regulatory requirements, and
2. aims to enhance customer satisfaction through the effective application of the system, including processes for continual improvement of the system and the assurance of conformity to customer and applicable statutory and regulatory requirements.

All requirements of ISO9001:2008 are generic and are intended to be applicable to all organizations, regardless of type, size and product provided. 

Where any requirement(s) of ISO9001:2008 cannot be applied due to the nature of an organization and its product, this can be considered for exclusion.

5. Everybody

You can't tell a single person is responsible for the quality of the project, because you cannot complete the project with a single person so team work is needed to complete the project, finally all the persons are responsible to maintain quality of the project.

1 .quality manager

Quality is every bodys responsibility

Everyone is responsible