If you’re selling shirts with a few different colours and sizes, WooCommerce’s variations feature will be fine, but we’re selling PCs with a list of attributes that results in over 12,000 possible combinations. We had to do a bit of tweaking to our web server’s memory limits, but the Bulk Variations Manager has enabled us to create and maintain as many combinations as we want and apply different attributes to different products. We would recommend this plugin to anyone wanting to sell complex variable products on WooCommerce.