Question: What do the Weather Factor metric and the CP Performance Since Last Departure traffic light in Fleet Overview mean?
1. Weather Factor
This metric, shown in Fleet Overview, quantifies how weather affects voyage duration, as a percentage. It compares the actual or predicted total time for a voyage leg against the hypothetical time to sail the same route in zero-weather conditions (no wind, waves, or currents), assuming identical fuel consumption.
Formula: Weather Factor = (Total Time / Total Zero-Weather Time) − 1
A positive value means weather is slowing the vessel down.
A negative value means the vessel is benefiting from favourable conditions, such as currents.
This isolates weather's impact on speed specifically — it doesn't account for routing changes.
2. CP Performance Since Last Departure
This traffic light indicator, also in Fleet Overview, shows how a vessel is performing against CP consumption expectations since its last departure.
A fitted fuel model is generated from good-weather noon reports since last departure (BF ≤ 5 and SWH ≤ 2.5m).
A "CP About" line is created by adjusting the CP line: −0.5 knots on speed, +5% on consumption.
The system compares the fitted model's predicted consumption against the "CP About" line for the vessel's current condition (ballast or laden).
The difference between predicted and actual consumption is shown as a percentage.