If you are using multiple machines in your production process, and it's important for you to assign them to particular work operations and to particular employees to work on them, there are a few steps that will enable you to do so.
Manufacturing > machines > add new
This will open a window where you can add a description of your machines and their serial number.
You also have a group section, where you can select the product category of this machine or choose the product category on which this machine is being used. You can also choose the trademark and shelf on which it is placed in the warehouse.
You have an open field, the detailed description, where you can enter any wanted information.
Once you've created the machine and saved the changes, when you start creating a new work order, you will have an additional column in the work operation section to choose the wanted machine from the drop-down menu.
You can also use a quick add option to add a new machine on the spot.
Now, when you enter each of the work orders from the list, you will be able to see which machine is being used in that production process.