Top-level context diagram

This example of a Top Level Context Diagram for an information system management process was redesigned from the Wikipedia file: IDEF Top-Level Context Diagram.jpg. [en.wikipedia.org/ wiki/ File:IDEF_ Top-Level_ Context_ Diagram.jpg]
"Graphical notation.
IDEF0 is a model that consists of a hierarchical series of diagrams, text, and glossary cross referenced to each other. The two primary modeling components are:
(1) functions (represented on a diagram by boxes), and
(2) data and objects that interrelate those functions (represented by arrows).
... the position at which the arrow attaches to a box conveys the specific role of the interface. The controls enter the top of the box. The inputs, the data or objects acted upon by the operation, enter the box from the left. The outputs of the operation leave the right-hand side of the box. Mechanism arrows that provide supporting means for performing the function join (point up to) the bottom of the box.
The IDEF0 process.
The IDEF0 process starts with the identification of the prime function to be decomposed. This function is identified on a “Top Level Context Diagram,” that defines the scope of the particular IDEF0 analysis. ... From this diagram lower-level diagrams are generated." [IDEF0. Wikipedia]
The IDEF0 diagram example "Top-level context diagram" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the IDEF0 Diagrams solution from the Software Development area of ConceptDraw Solution Park.

"Data flow diagrams are one of the three essential perspectives of the structured-systems analysis and design method SSADM. The sponsor of a project and the end users will need to be briefed and consulted throughout all stages of a system's evolution. With a data flow diagram, users are able to visualize how the system will operate, what the system will accomplish, and how the system will be implemented. The old system's dataflow diagrams can be drawn up and compared with the new system's data flow diagrams to draw comparisons to implement a more efficient system. Data flow diagrams can be used to provide the end user with a physical idea of where the data they input ultimately has an effect upon the structure of the whole system from order to dispatch to report. How any system is developed can be determined through a data flow diagram model.
In the course of developing a set of levelled data flow diagrams the analyst/ designers is forced to address how the system may be decomposed into component sub-systems, and to identify the transaction data in the data model.
Data flow diagrams can be used in both Analysis and Design phase of the SDLC.
There are different notations to draw data flow diagrams (Yourdon & Coad and Gane & Sarson), defining different visual representations for processes, data stores, data flow, and external entities." [Data flow diagram. Wikipedia]
The DFD (Yourdon and Coad notation) example "Process of account receivable" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Data Flow Diagrams solution from the Software Development area of ConceptDraw Solution Park.