What is draft analysis and why it is required?

To evaluate or double check ones work.

When making a part that will be molded, the analysis will verify that all surfaces are favorable for being pulled from a cavity.

It may also highlight or give insight to "trouble" areas.

Simple parts may not need this.

More complex parts that need multiple cores or slides, it becomes very helpful.

Better to check the part electronically than to create a mold that die locks.