Tracking and Invoicing Storage

My company sells and installs ATMs and other equipment for financial institutions. There are a small amount of customers who use our warehouses to store units that are not being used, which we bill for. We didn't have a way to keep track of these units or to remind us to invoice for the space and time being stored. Below is a breakdown of how I solved this in Wrike:

I created a 'Units in Storage' folder within our project management space.

From there I created folders for each customer who has a unit in storage, and tagged these folders to the customers folder in our 'customer' space. This allows for visibility for the sales team and anyone else outside of the PM team to see what is being stored from that customer.

Then within that folder, I added a task for each unit with a recurring date for the end of each year. 

This will act as our reminder to follow up with the client to see if they want to continue storing their unit with us, and if they do, we will bill them annually for the full year. We decided we would bill each customer who wants to continue storing their unit with us for the time until the new year, then charge annually after that, though you could easily switch this to a monthly reminder and bill monthly.

At this point my manager and myself are assigned to the unit tasks, and the recurring reminder will trigger us to follow up with the customer and then assign the task to our billing department for the final invoice.

I have also created a space for 'unassigned' units, which are just extra units that our company owns, with each unit as its own task, that way we can adjust the title of the task to reflect whatever needs to be done with the unit. Ex. Dispose of unit, move to office to be stripped for parts, etc.