A functional flow block diagram (FFBD) is a multi-tier, time-sequenced, step-by-step flow diagram of a system's functional flow.[2] The term "functional" in this context is different from its use in functional programming or in mathematics, where pairing "functional" with "flow" would be ambiguous. Here, "functional flow" pertains to the sequencing of operations, with "flow" arrows expressing dependence on the success of prior operations. FFBDs may also express input and output data dependencies between functional blocks, as shown in figures below, but FFBDs primarily focus on sequencing.
The FFBD notation was developed in the 1950s, and is widely used in classical systems engineering. FFBDs are one of the classic business process modeling methodologies, along with flow charts, data flow diagrams, control flow diagrams, Gantt charts, PERT diagrams, and IDEF.[3]
FFBDs are also referred to as functional flow diagrams, functional block diagrams, and functional flows.[4]
- ^ Systems Engineering Fundamentals. Archived 2011-07-28 at the Wayback Machine Defense Acquisition University Press, 2001
- ^ The first version of this article is completely based on the NAS SYSTEM ENGINEERING MANUAL SECTION 4.4 VERSION 3.1 06/06/06.
- ^ Thomas Dufresne & James Martin (2003). "Process Modeling for E-Business" Archived December 20, 2006, at the Wayback Machine. INFS 770 Methods for Information Systems Engineering: Knowledge Management and E-Business. Spring 2003
- ^ Cite error: The named reference
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