Techniques are described herein for customizing a form (a.k.a. a dialog) in a model-based system. For instance, the form may be customized without the need to modify the form in persistent memory, such as read-only memory (ROM), a hard disk, a magnetic disk, an optical disk, etc. A representation of a customization (e.g., an extensible markup language file, a management pack, etc.) regarding the form is captured in memory, such as a random access memory (RAM), and stored in a file or a database. For instance, the representation of the customization may be stored separately from the form. The representation of the customization is retrieved from the file or the database and applied to a rendering of the form.