Cart locking helps prevent data loss while a sales rep is working on a configuration. When a sales rep is working on a configuration (in edit mode), any other user who tries to access the cart at the same time will get redirected to a read-only view of the cart. The user in read-only mode can gain edit access only after the sales rep saves or finalizes or abandons or closes the cart.
A new custom setting, Enable Cart Locking for Concurrent Access has been introduced to handle the cart locking functionality. Available under Setup > App Setup > Develop > Custom Settings > Config System Properties > Manage, this custom setting enables your cart for concurrent access to other sales representatives.
A new field named Current User is added in the Product Configuration object which contains the ID of the user accessing the cart in the edit mode.