You will need to purchase the 'Organizer: Toolboxes' under the devices tab. After you have this and store items that run on electricity stuff will eventually break down. This is symbolized as items with a red cog over them. Pick up the toolbox and go the broken down item. Hold down left click on the red cog item on the broken down device and it will fix it. You can check your progress on the Manager Blackboard under the Statistics section. Once "Devices And Furniture Repaired" hits 30 you are good.
This achievement will unlock after you close your store for the night after you have repaired your 30th device.