There is a difference between Business Requirement and Functional Requirement. In Software Development Life Cycle, we prepare two different document to capture Business and Functional requirements. Now let us understand what Functional Requirement is and how Business Analyst will understand it.

“Functional requirements explain how a system should behave.”

Let us assume we are developing an Inventory Management system, which will be able to capture and store information pertaining to products in stock. The system will have many functionalities related to how the inventory details should be captured, how the inventory information will be retrieved etc.

Examples of how the inventory information will be captured –

1. FR# 1: The system should be able to allow Inventory Manager to add product inventory information.  
2. FR# 2: The system should be able to allow Inventory Manager to update existing product inventory information.  
3. FR# 3: The system should be able to allow Inventory Manager to delete product inventory information.  

As a Business Analyst, you also need to provide more details around what information will be captured while adding the inventory information in the system. Here we need to mention the field names, type of fields and mandatory field details. See the example below how we capture Complementary information with functional requirement for “Adding inventory” in the system:

Reference to FR#1

Following fields are required while adding the inventory information –

Fields	Data Type
Date	Date (MM/DD/YYYY)
Product Name	Text field
Product ID	Integer
Quantity in Stock	Integer

To ensure more clarity of the requirements, Business Analyst can also add flow diagram, use case in the functional description. This will provide more transparency to the technical team to understand the requirements so that they can design the system accordingly.