When you use a schedule compression technique, chances are you know you are not going to meet a deadline, and so even though it won't affect your schedule baseline, using this technique typically result in increased risk and/or costs. Therefore, in reality, project manager will do some initial calculation and risk analysis (e.g., staff acquisition, cost of overtime, etc.) to see whether it is viable to use this technique. If there is any impact in cost, change request is needed. If there is no effect (which is very highly unlikely) with any of the baselines , then you don't have to submit a change request.