why1. During rib top profile milling operation excess amount of material removed top surface due to that which was getting undersized|why2. The tool on Z axis direction moved into downwards|why3. The chips were blocked on ATC before loaded into tool holder due to that tool height Z value changed|why4. The empty pockets are available on machine during milling operation chips flowed on the empty pockets|why5. Due to that chips blocking on ATC tool downwards occurred on Z axis