USM allows you to make purchase order against demands or .This feature is available in Inventory module which can be accessed by clicking on the menu bar on the right of the screen.
Step 1. Click on the menu bar on the top right of the screen and select the Inventory module.
Step 2. Click on the option Purchase Order on the left of the screen.
Step 3. Click on the option Create Purchase Order on the top right of the screen.
Step 4. A pop up window will appear on the screen.Fill the form. After filling the form,click on the save option on the bottom of the dialog box.