In the Maintenance Module:
1. Under Spare Parts in the left grey bar, click on Stock.
2. If you have several Sites, click on Sites in the top blue bar and select the Site where you want to add some spare parts.
3. Click on the + icon in the top blue bar.
4. Select the Spare Part that you want to add.
5. Enter the quantity to add the stock for the selected Spare Part. You can also add a Comment.
6. Click on Confirm.