Barriers to JIT
The JIT operation is hampered by a significant number of major constraints. The following gives the list of constraints put on the master as far as the execution of the voyage is concerned:
- Contract of carriage (e.g. charter party) constraints: These include clauses on various aspects of ship operation that practically restrict some aspects of voyage management for energy efficiency. Charter party contracts, for example, normally put most of the power for ship speed management in the hands of the charterers. Financial impacts of deviation from charter party can be significant; thus, ship managers would do everything possible to avoid for example late arrival.
- Weather constraints: The weather along the route has impacts on the voyage management and vessel itinerary. To limit this impact, weather information and weather routing can be used.
- Route constraint: The route of the vessel may involve channel crossings, passing through pirate areas and the need for operations such as bunkering.
- Port constraints: Various ports impose various constraints on vessels. One major aspect is the competition between ships to arrive at port of destination in order to beat the queue. The system that dominates now is that most ships try to arrive early to the port in order to give their notice of readiness and stay in the berth queue.
- Other ship/owner/charterer specific constraints: These are specific constraints that may apply to various parties involved in ship operations including for example unexpected failures, delay in bunkering, etc.
All the above basically work against the JIT operation. They need to be avoided via improvement to the ship operation, charter party terms and conditions, staff culture, use of modern information technologies and systems such as weather routing and voyage monitoring systems (MariEMS 2017).