Hi I need help with creating a fishbone diagram. The problem is 'long queue at cashier' (in a grocery store). I am having trouble coming up more with categories and of these primary and secondary causes. It can be anything such as process, systems, method, material, etc.

I have done customer, staff, equipment, management, product already. Can you make some other suggestions?

Staff Customers Lack of training Poor customer service skills No show Goes back for other items Takes too long to order Poor work ethic Insufficient number of staff Complaints Prone to making errors Gives incorrect change Poor shift management Arrogant behavior Gets overwhelmed Long queue at cashier System not well organised Slow Promotions Poor system Poor planning Limited number of registers - Outdated technology Overcrowded store Product Management Equipment Eftpos machine broken