Just-In-Time (JIT) operation represents the optimal ship’s operation management from the perspectives mentioned. The JIT operation differs from slow steaming as the aim of JIT is not to go for drastic slow steaming but use all the measures possible within the voyage constraints (e.g. weather, charter party contracts, etc.) to reduce the voyage speed and thereby save fuel.
The main purpose of the JIT operation is to ensure that the ship’s operations are performed according to a “planned and optimised itinerary” with minimal time deviations. This means that vessels should never leave ports late or arrive in port of destination earlier than the planned itinerary. This will lead to the overall efficiency of the ship and port operations and to significant ship energy efficiency. The JIT operation benefit arises from the ship’s less waiting times and more passage time; thereby scope for speed reduction and thereby fuel efficiency (MariEMS 2017).