Shouldn't they be in your textbook? You should be able to find most of them in the glossary.
Anyway...
Inventory control - any strategy used for the control and monitoring of stock in your inventory. e.g. Just-in-time method.
Buffer stock system - I'm pretty sure it's the opposite of Just-in-time. That is, the business keeps lots of stock in its inventory, keeping a "buffer" so that it is rarely ever short on stock.
Just-in-time - A method of inventory control where only a minimal supply of stock is kept in the inventory. New stock is ordered very regularly. This is so that less cash is tied up in stock that can be used to pay liabilities.
Layout - This usually refers to the layout of the plant or production facility when manufacturing that shows the position of the equipment. Mostly concerned with efficiency of production.
Technology - This is broad and ambiguous...
Key business functions - Should have learnt them in Year 11. They are the different functions that a business usually requires in order to operate, and are normally separated into different departments in large firms. They are Marketing, Employment Relations, Accounting and Finance, and Operations.
