If you are working with projects then you might want to consume items and bill them through your project. You can do this with an item requirement. Essentially this is a sales order that you manage from your project. From there you can create the pick and invoice. Now the pick will be handled if you do small amount of items by a paper process and could have a warehouse or inventory team involved for larger scale operations. It’s important to note that if you are looking at using the advanced warehouse in R3 then you will need to be using CU10. The overview below is CU9 for a simple process without warehouse.
Here is a quick walk overview.
AX2012 R2 CU9.