An illustration of that is the function block diagram, among five programming languages found in part 3 of this IEC 61131 (view IEC 61131-3) standard that's very formalized (see proper method ), with stringent rules to how diagrams must be built. Directed lines have been used to connect input variables to block input signal, and block outputs to output variables and inputs from different blocks.
In biology there's a growing use of engineering principles, techniques of evaluation and ways of diagramming. There's some correlation between the block structure and what's named Systems Biology Graphical Notation. Since it is there is use made in systems economics of this block structure technique exploited by controller engineering where the latter itself is a program of management theory.
For example, a block diagram of a wireless isn't anticipated to demonstrate each and every connection and dial and switch, but the design diagram is. The schematic diagram of a radio doesn't show the diameter of every link in the circuit board, however, the layout diagram will not.
In electrical engineering, a style will often start as a quite large level block diagram, getting increasingly more detailed block diagrams because the design develops, eventually ending in block diagrams detailed enough that every individual block is readily implemented (at that point the block diagram is also a schematic diagram). This is known as top down layout.  Geometric shapes are often used at the diagram to aid interpretation and describe meaning of this process or model. Each engineering field has their own significance for every form. Block diagrams are employed in every discipline of engineering. They are also a valuable source of concept building and educationally valuable in non-engineering areas.
Block diagrams are usually used for higher degree, less detailed descriptions that are intended to clarify general theories without issue for the details of execution. Contrast this with the schematic diagrams and layout diagrams used in electric engineering, which reveal the implementation details of electrical components and physical structure.
A block diagram is a type of a system where the principal parts or works are represented by blocks connected by lines that reveal the connections of the blocks. They are heavily utilised in engineering in hardware design, digital design, software design, and process flow diagrams.
In process management, block diagrams are a visual vocabulary for describing actions in a complex system where blocks are black boxes which represent mathematical or logical operations which take place in sequence from left to right and top to base, although not the physical things, like processors or radiators, that execute those operations. It is likely to create such block diagrams and implement their performance with specialized programmable logic controller (PLC) programming languages.
Block diagrams rely upon the principle of the black box where the contents are hidden from view either to avoid being distracted by the facts because the details are not known. We understand what goes in, we know what goes out, but we can not see the way the box does its work.
To make an analogy to the map manufacturing planet, a block diagram is similar to a highway map of an whole nation. The major cities (functions) are recorded but the small county roads and city streets are not. When troubleshooting, this large degree map is useful in narrowing down and isolating where a issue or malfunction is.