business process or business method is a collection of related, structured activities or tasks that produce a specific service or product (serve a particular goal)

 

another definatiion applied may be :
a structured, measured set of activities designed to produce a specific output for a particular customer or market. It implies a strong emphasis on how work is done within an organization, in contrast to a product focus’s emphasis on what. A process is thus a specific ordering of work activities across time and space, with a beginning and an end, and clearly defined inputs and outputs: a structure for action. … Taking a process approach implies adopting the customer’s ( or marketplace)  point of view. Processes are the structure by which an organization does what is necessary to produce value for its customers.”