DB Design - Mailing list pgsql-sql

I have a inventory system design in which I would like some help with to 
see if it's efficient.  The products are broken into:

Product tables
Property tables
Configurable Products - this would include colors (i.e. - black, blue 
and green) tied to products

I'm thinking of breaking inventory into 2 tables.

Product Inventory
Inventory Adjustment

Should I include the fk of the Configurable Product in the above tables 
or break it out further into more tables?

Product Inventory
Inventory Adjustment
--plus--
Product  Property Inventory
Inventory Property Adjustment

Thanks for any input,
J

These are my Product tables:

\d cart_product                                      Table "public.cart_product"     Column       |           Type
    |                         
 
Modifiers                        
-------------------+--------------------------+-----------------------------------------------------------id
   | integer                  | not null default 
 
nextval('cart_product_id_seq'::regclass)name              | character varying(128)   | not nullkind              |
charactervarying(40)    |sku               | character varying(15)    |short_description | character varying(255)   |
notnulldescription       | text                     |category_id       | integer                  | not
nulldate_created     | timestamp with time zone | not nullactive            | boolean                  | not
nullin_stock         | boolean                  | not nullfeatured          | boolean                  | not
nullordering         | integer                  |
 
Indexes:   "cart_product_pkey" PRIMARY KEY, btree (id)   "cart_product_category_id" btree (category_id)
Foreign-key constraints:   "cart_product_category_id_fkey" FOREIGN KEY (category_id) REFERENCES 
cart_category(id) DEFERRABLE INITIALLY DEFERRED


\d cart_propertyvariation                                   Table "public.cart_propertyvariation"   Column     |
Type          |                              
 
Modifiers                             
---------------+-----------------------+---------------------------------------------------------------------id
  | integer               | not null default 
 
nextval('cart_propertyvariation_id_seq'::regclass)properties_id | integer               | not nullname          |
charactervarying(42) | not nullvalue         | character varying(20) | not nullorder         | integer               |
 
Indexes:   "cart_propertyvariation_pkey" PRIMARY KEY, btree (id)   "cart_propertyvariation_properties_id" btree
(properties_id)
Check constraints:   "cart_propertyvariation_order_check" CHECK ("order" >= 0)
Foreign-key constraints:   "properties_id_refs_id_73bc0a59" FOREIGN KEY (properties_id) 
REFERENCES cart_property(id) DEFERRABLE INITIALLY DEFERRED


\d cart_configurableproduct                               Table "public.cart_configurableproduct"    Column      |
Type    |                               
 
Modifiers                              
-----------------+--------------+-----------------------------------------------------------------------id
|integer      | not null default 
 
nextval('cart_configurableproduct_id_seq'::regclass)product_id      | integer      | not nullvariation_id    | integer
   | not nullprice_change    | numeric(8,2) |weight_change   | integer      |quantity_change | integer      |active
    | boolean      | not null
 
Indexes:   "cart_configurableproduct_pkey" PRIMARY KEY, btree (id)   "cart_configurableproduct_product_id" btree
(product_id)  "cart_configurableproduct_variation_id" btree (variation_id)
 
Foreign-key constraints:   "cart_configurableproduct_product_id_fkey" FOREIGN KEY (product_id) 
REFERENCES cart_product(id) DEFERRABLE INITIALLY DEFERRED   "cart_configurableproduct_variation_id_fkey" FOREIGN KEY 
(variation_id) REFERENCES cart_propertyvariation(id) DEFERRABLE 
INITIALLY DEFERRED