Typical Processes in Data Flow

4.3 Typical Processes
Now we shall discuss processes which are typically modeled using data flow diagrams. These processes transform data in one or the other way but these are found in almost all the automated systems. Following are the examples

•  Processes that take inputs and perform certain computations. For example, Calculate Commission is a process that takes a few inputs like transaction amount, transaction type, etc and calculates the commission on the deal.
• Processes which are involved in some sort of decision-making. For example, in a point of sales application a process may be invoked that determines the availability of a product by evaluating existing stocks in the inventory.
• Processes that alter information or apply a filter on data in a database.

For example , an organization is maintaining an issue log of the issues or complaints that their clients report. Now if they want to see issues which are outstanding for more then a weeks time then a filter would have to  be applied to sort out all the issues with Pending status and whose initiation date is a week old.

•  Processes that sort data and present the results to users. For example, we pass an array of arbitrary numbers to a QuickSort program and it returns an array that contains the sorted numbers.
• Processes that trigger some other function/process 

For example, monthly billing that a utility company like WAPDA, PTCL generates. This is a trigger that invokes the billing application every month and it prepares and prints all the consumer bills.

• Actions performed on the stored data. These are called CRUD operations and described in the next subsection 

CRUD Operations
These are four operations as describes below

• Create: creates data and stores it.
• Read: retrieves the stored data for viewing.
• Update: makes changes in an stored data.
• Delete: deletes an already stored data permanently.