The Nature of Temporal Progression in System Diagrams
Sequence connections describe pure chronological progression: stage A finishes before stage B begins. Unlike data flow connectors that transport payloads or dependency lines that represent structural coupling, a sequence arrow establishes strict temporal precedence across operational phases.
A common breakdown in technical documentation happens when teams use generic arrows to represent sequential order while simultaneously implying data transfer. When engineers inspect a sequence connector labeled simply with an arrow, they frequently assume payload delivery occurs automatically across that edge. Without explicit semantic separation, readers confuse the completion of a milestone with active invocation or state transmission.
The Sequence Disambiguation Formula
Evaluate the relationship using: Two Nodes → Possible Meanings → Evidence From Context → Better Label → Remaining Ambiguity. If Node B only requires that Node A has finished without consuming Node A's direct output, label the connection strictly as "precedes" or "followed by" rather than "sends data to".
Chronological ordering demands unambiguous edge definitions. When asynchronous tasks run in coordinated order, labeling the connectors with explicit phase markers prevents system architects from designing unnecessary message queues or direct API couplings where only a schedule dependency exists.