Using Add Module... to import a Model file
An Analytica (
*.ana) file may contain a Model, Module, or Library as its top level object. (Any of these objects may, of course, contain subModules.) A Model file, unlike a Linked Module or Library, usually contains settings for various System variables (such as Time and SampleSize) and Preferences, set in the Preferences and other dialogs.
When running a Model
M1 and you use Add Module... to import a Model file
M2, it shows the dialog below (in Analytica 4.2.2 and later). This dialog lets you decide whether you want to retain all the current settings for
M1 (answer "Yes") or apply any nondefault settings from
M2 (answer "No").
Analytica 4.4: Answering No reads in the system variable settings from the imported file, answering Yes leaves your current system variable settings in tact.
Analytica 4.3 and earlier: (Yes and No are the other way around -- Yes reads in settings from the imported file.
If you are linking (rather than embedding), the model will remember your answer. However, beware that a linked file may be saved if it is dirtied in any way, thus causing the system variables in the file to be replaced. Also, when linking, the checkbox at the bottom appears, giving you the option of converting the top-level object in the file being linked to a linked module. Note that this will cause the system variable settings to be lost when the model is saved.
In general, if you intend a file to be shared between models, don't use a Model class. Change the class of the top-level object to LinkModule or LinkLibrary.