Simple Products not showing as associated in configurable products

To associate them

not needed:

• visibilty = not show inidividually
• stock = in stock
• price = also set
• status = enable

needed:

• attribute set = the same as configurable product

to create a config

Beside this you need to make sure, that the attributes you want to be configurable are NOT system, "Global", input type "Dropdown" and "allowed for configurables"

to show them in frontend

Only the simple ones which are in stock and enabled are shown in frontend, might be an indexing issue?

Make sure that you associated the simple products with the configurable product. Therefore, go to the configurable product, open the "Associated Products" tab, select the appropriate simple products and save. If you do not see your simple products there, make sure to click on "Reset Filter" (and that your simple products have the same attribute set as your configurable one). As always, you may need to reindex or clear your cache.

Also, if you do not see the products in the associated tab, even after resetting the filter, check that the attributes that are configurable, have a correct value in the simple product. I loaded lots of simple products via import, but for some simple products the color or size attributes were empty and could not be found. Make sure all attributes that are marked in the configurable products as "configurable" are filled.