How to Create a Workflow to Change Item Level Permissions
Change Item Level Permissions In SharePoint 2010 there are item level permissions that can be applied on lists. Essentially you can mouse over each item, click on the drop down arrow, and choose Manage Permissions. On the permissions page you can choose the Stop Inheriting Permissions button on the ribbon and then customize the permissions on that item. Now you have the desired results across the board without needing to setup web parts with Audience Targeting. However, this approach has a couple of flaws. First, this method can be very daunting to manage especially for large lists. Think of breaking the permission inheritance on each and every item in the list and then customizing the permissions. Also think about managing it going forward, what happens when you have to add a new user to permissions? Since inheritance is broken on the item you will have to manually add that new user to each item that they should have access to. You could and should use groups