Is a Function the Same a Functionality?
I was recently asked by Jan van Bon from the Netherlands to define “the difference between a Function and Functonality”.
My reply was,
“A Business Function (or Function) is a core activity of an enterprise. It is something that the enterprise must do in order to meet its objectives and continue in existence.
Examples, of functions would be, ‘Sell Product to Customer’, ‘Bill Customer for Products Delivered’, ‘Recruit Employee’, etc.
‘Functionality’ is a general English phrase that is generally used when referring to a computerised system in defining what Business Functions the system fully or partly supports.”
Jan then came back with the following additional questions:
“You say a Business Function is a set of activities. Then let me ask you the next question:
- does a function include people and knowledge?
- does a function include products?
- does a function include all of these?
- is a function a result?”
Let me address these questions one at a time.
Does a Function Include People?
A Function does not include people. It may be performed by people but, alternatively, it could be fully automated and require no human input.
Does a Function Include Knowledge?
Well this depends on your definition of ‘knowledge’. All Functions require information (data in a context) as an input and may transform this information or create new information. As such, every Function will have an information output.
Every function will contain function logic and may also include business rules. In fully automated Functions, these will be built into the module executing the Function. Is this knowledge? Well perhaps it is as, without having the logic and business rules built into an automated module, humans with that knowledge would be required to perform the Function.
Does a Function Include Products?
A Function will always result in a product either physical or abstract. For example:
|Manufacture Autoparts||Manufactured autoparts.||Physical|
|Recruit Employee||Recruited Employee.||Abstract|
|Calculate Tax||Calculated tax on item.||Abstract|
Does a Function Include All of These?
As the answers above show, sometimes ‘yes’ and sometimes ‘no’.
Is a Function a Result?
No a Function is not a result.
A Function is an activity that brings about a result. That result will be the delivery of the product for the Function, together with all of the information necessary to be able to ascertain that the Function has been successfully completed or, if not successfully completed, rolled back to the starting state.
Note: Function is synonymous with Business Function.
Read more on Business Function Modelling