For often, a perfect tool is even not sufficient to comply with the needed quality level of gears. This is particularly true when it is necessary to address requirements such as optimizing noise level. In such cases, built-in sensors of the injection machines are not anymore sufficient to control in an appropriate way the injection process. These machine sensors provide indeed an information that is too far from what occurs into the cavities themselves and this is not then consistent with the expected accuracy level of the parts. To solve this concern, it may be necessary to control the injection process, through out sensors that are directly measuring pressures and temperatures in the cavities. This approach combined to the attention we pay in designing and manufacturing our tools allows us to achieve a precision of our gears never achieved before.