how to inhibit the editing of goals in the performance document

Hi,

we want to inhibit the possibility for the employee and the manager to edit the goals in the self-assessment and managerial evaluation phase in the performance document.

Goal setting phase is separated from the performance document, goals are set by the employee (with approval process) and assigned by the manager on the goal page of the direct report.

The performance document includes these steps:

1. self-evaluation of the employee;
2. managerial evaluation;
3. acknowledgement and final feedback of the employee.

During the self-evaluation and managerial evaluation phase, goal basic info and measurements are editable by manager and employee.

I would like to know whether there is a possibility to make goal basic info and measurements not editable during these two steps, only the "Actual Value" field must be editable during self-evaluation and managerial evaluation.