From what I’ve seen in industry the changes have varying degrees of difficulty. Changes during the design control phase are easier than when the system is in production. At any time, SOP’s seem to me the easiest, though that doesn’t mean that they’re necessarily easy. The bill of materials (BOM) is harder than SOP’s especially if after the control phase due to the need for a change control to determine if the product will be affected. The same applies to the design control documents. If I understand what the Master Record is, it is harder than the SOP’s but easier than the others. This is because it’s the collection of all of the work and changes made to the system. cGMP requires the retention of all of these anyway so a proper retention system makes it easy to add to the current record. What do you guys think? Have a different order in mind?