In terms of television and film production, the Visual Effects Supervisor is the person who is responsible for accomplishing the creative aims of both the producer and director of the film, through visual effects. They are the technical manager and creative, who are managing the work of the staff (composing of concept artists, animators, modelers, etc.), devoted to the art and science of visual effects. He or She is responsible for the technical, and creative issues of the VFX on a project and the task will begin in the pre-production phase until the completion of the VFX in post-production phase, which usually spans to one to two years on a big project.
During the shooting of the film or television show, the supervisor is responsible for leading his/her staff through any needed research and development of software and tools. While on the set, he/she should monitor the shooting to guarantee correct lighting, proper sight lines for the artists, shot framing, and other components needed for perfect integrating VFX sequences."