Executive
Project administration is done by Project Management
The person or team assigned to the project is responsible for its completion.
a executive is a person responsible for the administration of a business
A project manager is the person responsible of planning, managing, executing, and controlling the project.
The budget owner is the person responsible for managing the financial resources of the project.
Thomas was responsible to bring Christianity to India.
manager
A person responsible for an administration. A person or group of persons having administrative or supervisory authority in an organization.
The Project Manager is responsible for delivering the Project. S/he is the person leading and managing the Project team.
The secondary reviewer for this project is the person responsible for evaluating the work after the primary reviewer has completed their assessment.
A project manager can be absolutely critical to the completion of a project. The project manager is the person responsible for all aspects of a project coming together and is typically the one who is ultimately at fault if the project fails.
The specific title might be "overseer" but that is seldom used in a modern context, such individuals being called "project managers" among other things.