Data and process modeling involves three main tools: data flow diagrams (DFD), a data dictionary, and process descriptions. A DFD represents system requirements as processes, external entities, data flows, and data stores. A DFD shows what a system does, not how it does it. Because DFDs are graphical models that use a limited number of symbols, DFDs can be read and interpreted by information system workers, end users, and management, which makes them a valuable tool for communication. A process can be a procedure or an algorithm. Data flows represent data movement among processes, data stores, and external entities. Because data emerges without any apparent source, some analysts refer to a spontaneous generation process as a miracle. A data store represents a file or part of a database. An external entity (sometimes called external agent) is outside the system boundary but supplies input or accepts output.

What are three benefits of modeling and why are they important?