Block Diagrams of Functions

Block diagrams that illustrate the interrelationships, operation, and interdependencies of the functions of a system are required to show the sequence and the series dependence or independence of functions and operations. Block diagrams might be constructed in conjunction with, or after specifying the system & shall present the system breakdown of its major functions. More than one block diagram is occasionally required to represent alternative modes of operations, based upon the definition established for the system.

Functional Block Diagrams

Functional block diagrams illustrate the operation and interrelationships among functional entities of a system as defined in engineering data and schematics. An instance of a functional block diagram, taken from MIL-STD-1629, is illustrated in the following Figure.

                                                              Figure : Functional Block Diagram

Reliability Block Diagram

Reliability block diagrams define the series dependence, or independence, of all of the functions of a system or functional group for each life-cycle event. An instance of a reliability block diagram, taken from MIL-STD-1629, is illustrated in the following Figure

                                                                 Figure : Reliability Block Diagram