I have two custom fields - one is called "requirement" and other is called "Approved requirement". I'd like for the "Approved requirement" custom field to be non-editable, except by certain users (for ex. project manager). When an issue is created, the requirement text is entered into the "requirement" field. An approval workflow will be created to ensure that the project manager reviews and approves the "requirement". Once approval is provided, I'd like for the "Approved Requirement" field to be populated with the text from "requirement".
If automated update of the "Approved Requirement" is not possible, the project manager can manually update the "Approved Requirement". Regardless, the key is that read/write access can be determined for the "approved requirement" field.
How can I implement this?