Task Flow in Task Dependency is progression of dependent consecutive tasks and their sub-tasks that comprise a process or project and create or add value to this process/project with consumption of resources. It is a sequential workflow in which every task is dependent on occurrence of the previous task or sub-task.
Elements of task flow are tasks and sub-tasks that are logically linked to each other. Task flow is often presented as a hierarchy in which includes two or more decomposition levels. Each higher level determines a series of tasks which subordinate other tasks and sub-tasks from lower levels. All elements and levels of task flow hierarchy are defined by dependency rules.
Task flow diagram is best to use to display elements and levels of task flow hierarchy. Such a diagram creates a model of dependent tasks and graphically shows relationships between these tasks. Every larger task in the diagram is presented is parent or root and decomposed into smaller (child) tasks and sub-tasks. Relationships between the root task and its child tasks are displayed by graphic lines and arrows.