Design Functional Decomposition Based on Flow

Technological complexity and faster revision have led to an increasingly complicated design process; hence, there is great interest in such issues as efficiency and reliability. The focus of this paper is a conceptual (in contrast to mathematical or logical) analysis to assist in accomplishing such a task. Specifically, the paper focuses on the design phase of functional decomposition, in which an overall function can often be divided into identifiable subfunctions corresponding to subtasks. Many diagrammatic languages in this field utilize a block diagram in which the processes and subsystems are understood to be inside a given block (black box), and with functions usually defined by statements consisting of a verb and a noun. But this type of diagrammatic representation suffers from many shortcomings. Flows are intermingled with a control flow, the whole is mixed with its parts, and the number of potential types or names of constructs is enormous. The paper proposes an alternative description based on pure flow and triggering made up of five basic stages. The two approaches are contrasted through examples. The results point to a conceptual improvement gained by use of the proposed method as an abstract formulation of tasks.