Marine Solver was conceived from the start as a tool at the intersection of rigorous optimization and real-world shipping practice. Its goal is not to showcase how complex a model can be, but to carefully embed mathematical logic into the process of commercial decision-making — where uncertainty, alternatives, and strategic considerations are always present.
In shipping, optimization never exists in a “pure” form. Any decision is compared not to an abstract maximum, but to what is available in the market, what is operationally feasible, and what aligns with the company’s long-term objectives. This context is what defines the Marine Solver philosophy.
Continuous Planning as the Foundation of Efficiency
At the core of Marine Solver lies the idea of continuous planning (although the user can still obtain a single voyage if that fits their business philosophy or current priorities). In general, however, the tool is designed not simply to select one voyage, but to construct a sequence of voyages over a defined planning horizon — either by that horizon itself, or by the number of links the user specifies (the number of cargoes and the vessel’s desired/required exit point).
This formulation reflects the real logic of fleet operation. A vessel does not exist within the boundaries of a single voyage — it operates through time. Idle time, waiting for the next cargo, and gaps between operations often prove more expensive than “non-ideal” voyages that are nevertheless logically connected.
This is where Marine Solver already structurally improves operating efficiency. Reduced idle time, more coherent route continuation, fewer “empty” days — all of this directly affects time-normalized performance. Even if individual voyages within a chain do not look optimal by classical metrics, the aggregate outcome over the planning period is often better.
From a practical perspective, this may mean that a company incurs somewhat higher transaction costs at the initial stage - to form a voyage chain, align terms, and structure combined decisions. Yet in total, these costs are often lower than the cost of fragmented operations, where each voyage is searched for and fixed separately. When you look at the period as a whole, the alternative is almost always more expensive.
Why TCE Is Already “Maximized” in Marine Solver’s Logic
The idea of continuous planning, in essence, corresponds to maximizing a vessel’s efficiency over the planning horizon. In this sense, one could say that Marine Solver already works in the direction of higher TCE - not by directly optimizing the formula, but by removing structural sources of inefficiency in operations.
Even when optimizing a single voyage, the tool considers its place in a chain (the first link - the vessel’s open position - almost always turns a standalone voyage into part of a chain, except in the case where the cargo is in the same port. And even then, a “match” is not necessarily the best decision). When working with a planning horizon or with a specified number of voyages, this logic becomes even more pronounced. Solver aims to ensure that the vessel operates continuously and meaningfully over time - and that is exactly what metrics like TCE are intended to reflect.
Chains, Market Imbalance, and Managed Risk
Freight markets are rarely symmetric. There are often regions with high earnings and regions where a river needs to reposition - for strategic, commercial, or operational reasons. In such cases, a single voyage may look weak, while a voyage chain can be strong.
Because Marine Solver can account not only for the vessel’s point of availability but also for the desired exit point, the user can load cargoes from different regions and link them into a chain where the first leg acts as a “migration” leg, and the second becomes commercially strong. Overall efficiency is assessed across the full planning horizon, not by isolated fragments.
In this way, Marine Solver does not impose maximum utilization at any cost. It provides a tool for deliberate chain management, where efficiency is achieved not through a single “perfect” voyage, but through the logic of how the vessel moves across space and time.
Therefore, the question is not whether we ignore TCE. The question is what role this metric should play in the model. Maximizing profit over a fixed time horizon is mathematically equivalent to maximizing average TCE over the same period - but it is much more stable and captures those very “empty” ballast days far better.
TCE as a Benchmark, Not an Optimization Target
Historically, Time Charter Equivalent has never been a standalone optimization objective. It is a benchmark. A normalized “per day” indicator that allows one to compare voyages of different durations, compare spot operations with time-charter alternatives, and answer a key practical question: does this voyage make economic sense compared to the available alternative?
This is exactly how TCE is used in Marine Solver. We treat it as a benchmark, a reference point, a threshold of economic acceptability - not as a quantity that must be maximized at any price. In scenario metrics, users see time-normalized efficiency indicators - profit or costs normalized by time. These indicators matter: they allow scenarios to be compared. But they remain an analytical instrument, not an optimization objective in itself.
External Alternatives and the Role of Thresholds
In real operations, a vessel almost always has an external alternative. For an owner, it may be fixing the vessel on time charter or declining a voyage. For a TC-in operator, it may be rejecting an economically unjustified route. These alternatives exist outside the model, but they are precisely what defines the acceptability boundary for solutions within it.
That is why Marine Solver uses TCE-like indicators in the form of threshold constraints. A solution must not only be optimal within the model; it must also be no worse than the efficiency level the user considers acceptable, based on the market, the company’s strategy, and their own experience.
This approach allows a clear separation of two different questions. The first: does the solution make economic sense at all? The second: which of the economically sensible solutions is better? Threshold indicators answer the first question, while profit optimization or cost minimization answers the second.
Why We Don’t Optimize Relative Metrics Directly
From a mathematical standpoint, direct optimization of relative metrics such as TCE is possible. However, it leads to more complex models, increases computation time multiple times, and makes results highly sensitive to edge effects. More importantly, it does not always answer the managerial question the user is trying to solve.
In practice, it is rarely important to know where the absolute maximum of a relative metric lies. It is far more important to identify solutions that are robust, explainable, and genuinely better than the available alternatives. Maximizing profit or minimizing costs subject to a given efficiency level is often more meaningful from the standpoint of a company’s long-term objectives.
Over the long term, performance is assessed not only by “per day” efficiency, but also by absolute outcomes and by efficiency “against costs.” Profit, profitability, return on invested capital - these are the metrics that define business resilience, not only operational efficiency over a specific period.
Using TCE as a benchmark rather than as an optimization target preserves the link to the market without replacing strategic goals with a relative metric. It makes the model more stable and the results more interpretable.
The Marine Solver Philosophy
Marine Solver deliberately chooses this path. It is not a rejection of mathematics, and not simplification for the sake of convenience. It is an attempt to preserve balance between formal optimality and economic meaning - between what can be optimized and what is truly worth optimizing.
The tool is not meant to replace the user’s professional judgment. It creates a transparent framework in which decisions remain economically justified, comparable to the market, and applicable in practice.
Marine Solver turns TCE from a capricious target - one that is easy to chase and still lose money - into a strict quality standard. We are not looking for a “pretty number.” We are looking for a profitable strategy that is validated by a market benchmark.