Hi,
Regarding your Data Validation scenario it is a Functional requirement. It cannot be Non functional.The data quality is essential for further processing of application, if the format or parameters are incorrect it will impact the functioning of the system viz processing, manipulation of those data , generating reports.
For the second scenario difference between a Business Requirement and Non-Functional Requirement? Are they the same in the following example? "The supplier shall adopt the company's change control policies whenever possible".In this scenario in my view the non-functional requirement will be aligned to the business requirement.
I consider an example that the change control policy for an Insurance company is to go paperless. The policy documents should be only electronic and no option of printing document is available to Insurers.
Incase they need then it will be sent by postal mail from the Insurance company.
The business requirement will be:
1.Checking valid credentials of Insurer
2.When the Insurer needs a document it must allow to save a copy in his/her system or email it
3.Incase the Insurer needs the document as paper then it must be raised as request to the Insurance company later it will be sent in postal mail.
4.Request from the Insurer will be received by the administrator who will initiate document to be mailed to their respective address.
The NonFunctional requirements will be:
- Display screen and menus for different types of users i)Insurer ii)Administrator
- Policy document displays in 5 seconds
- Email to be sent within 5 seconds
- Number of Insurers who are allowed for concurrent access for a specific documents
Non functional requirements are part of Business requirement they doesn't affect the basic function of the system or application.They are vital as they impact security,usability,availability and they lean towards the external features. Some times they may seem cosmetic too.
I hope this response helps.