Software applications are a combination of elementary processes. When elementary processes come together they form a software application.

There are two types of elementary processes:

Dynamic elementary Process: The dynamic elementary process moves data from an internal application boundary to an external application boundary or vice-versa. Example: Input data screen where a user inputs data into the application. Data moves from the input screen inside the application.

Static elementary Process: Static elementary process which maintains the data of the application either inside the application boundary or in the external application boundary. For example, in a customer maintenance screen maintaining customer data is a static elementary process.