One of the weaknesses of the basic Zen Cart application is the ability to quickly and easily manage the inventory values of products that use atttributes or variants. Base Zen Cart functionality was not adequate.
The Numinix Product Variants Inventory Manager was just what we needed. This enhanced inventory manager allows us to navigate and update inventory with ease.
If you use products with variants, this module is an absolute must. The only caveat is that installation of this module will significantly change the database structure. You must be careful if you are using any 3rd party software to access the MySQL database.