This paper presents the progress made in the prototyping of a Crop Model Factory. This method is intended to be used by agronomists to design scientific models and to produce the corresponding Java code to be used in a web-based decision support system. A subpart of a legacy vine model is used throughout the paper to illustrate the advances of the prototyping phase. Note that the version of the prototype presented in our previous papers was very basic. The new software version described here includes numerous fully functional components (e.g., new graphical user interface, model serialization) and provides Java code generation. The present paper focuses only on these new elements.