Chapter 5 Building Dynamic Diagrams

Synchronizations (OOM)

A synchronization is an object that enables the splitting or synchronization of control between two or more concurrent actions.

Synchronizations are represented as horizontal or vertical lines. You can change the orientation of the symbol by right-clicking it and selecting Change to Vertical or Change to Horizontal from the contextual menu.

A synchronization can be created in the following diagrams:

Activity Diagram
Interaction Overview Diagram

A synchronization can be either:

Fork - splits a single input transition into several output transitions executed in parallel. It creates several concurrent branches below its symbol. The activities associated with each of these paths continue in parallel and represent an independent transition (or control flow):
Join – merges multiple input flows into a single output flow. The activities associated with each of the paths above the join symbol are parallel. In a join, concurrent transitions synchronize. Each transition waits until all input flows reach the join before continuing; the first executed transition waiting for the last one to complete. After the join, only one transition continues below the join.