1) Create an Ingredients Category
To avoid all the ingredients popping up in the Point of Sale module when a cashier/waiter is busy selecting products, create a separate category for ingredients.
Check the box 'Hide in POS Modules'.
2) Add the Ingredients as Products
Lets say the shop receive the potatoes in 7 KG bags, then we add a product called 'Potatoes 7 kg'. Remember to select the 'Ingredients' category to prevent this item from showing up at the till.
3) Add the items that you want to sell
Lets say a 'Small Chips' use 560g of potatoes.
That means from one 7 kg bag it will use 0.08 potatoes (560 / 7000 = 0.08 ).
So when we create our 'Small Chips' item, we add potatoes as a sub item and change the number to 0.08.
In the same way we can add other items. For example a Large Chips that will use 1 kg potatoes, will be 0.14.
4) Receive your Stock
Lets say we then receive 2 bags of 7KG potatoes
We go to stock receiving, select 7kg potatoes and enter 2 for quantity received.
Our stock on hand will now be updated to show how much potatoes we have in store and how much we can make with the available stock.
Lets say you then sell 1 large chips (1kg potatoes) and 3 small chips (560g x 3), the system will then calculate how much potatoes should be left.
You will then have 1.62 bags of potatoes left.