SSD stands for system sequence diagrams. SSd diagrams <span>model the interactions between objects in a single use case and illustrate how the different parts of a </span>system<span> interact with each other </span> On an SSD, a dashed arrow usually represents an object. SSD <span>depicts the </span>objects<span> and classes involved in the scenario and the </span>sequence<span> of messages exchanged between the </span><span>objects.</span>