Level 0 data flow diagram of a food chain system is here.

We have to Decompose Process 1 and Process 4 into sub processes to make a Level 1 DFD

CUSTOMER KITCHEN 1.0 Customer Order Receive and Food Order Receipt Transform Customer Food Order 2.0 3.0 Goods Inventory Update Sold Data Update Goods Sold Inventory File File Formatted Formatted Goods Sold Data Inventory Data Goods Sold Inventory D2 File D1 File Daily Goods Sold 4.0 Daily Inventory Amounts Depletion Amounts Produce Management Management Reports Reports RESTAURANT MANAGER