The purpose of polymer processing modelling is certainly the identification of optimal processing conditions. However, the word optimal is more and more considered related to the properties of the final object, and the properties are determined by the morphology distribution. Thus, nowadays, the modelling of polymer processing is expected to give reliable indications at least about the morphology distributions in the final object. This requires the identification, above the process modelling and simulation, of models for the prediction of morphology formation during the process in the final product. Furthermore, if the aim includes the prediction of properties of the final object, one needs to identify, for each property, a criterion for their prediction based on morphological characteristics. This route will be described in detail in relation to the injection molding process of an isotactic polypropylene, iPP. In particular spherulitic, fibrillar or intermediate morphologies are found in the moldings depending on local molecular stretch in the final moldings. In particular, spherulitic morphologies form in the cavity central area (where the shear rate is small), vice versa fibers form where the shear rate is high (namely at the cavity surface) and, furthermore, the fiber thickness decreases where the molecular stretch increases. At the cavity surface, if the cooling rate is higher than a critical value, the polymer does not have the time to achieve an adequate structuring during its cooling and, consequently, a thin unstructured layer, free of fibers, is observed. Obviously, better mechanical properties were found in positions where structure is fibrillar with respect to sferulitic structures. Also the structuring accuracy achieved during crystallization is very relevant to the final local mechanical properties: the structuring accuracy is found to improve as the time that the polymer spends at the crystallization temperature increases, but it also depends on the level of this temperature.