Commerce AutoSKU is a really useful tool for those Drupal Commerce users that don't need or don't care about generating their own SKU identifiers. This module uses the Drupal core capabilities to manage tokens and generate SKU for the products based in other product properties such as title, product id or any other token available in the product context. Additionally, the contributed Token module helps a lot with the selection of the pattern.

The automatic SKU generation can be configured at the product type level and the SKU field can be hide to the administrator users, it also supports case transformation and other settings.