Stowage Quality Influences

Stowage is a non-linear process:

“This is a function that has too many factors to be computed using linear mathematics. This is the reason why we as humans consider ourselves so extraordinary, the ability to solve non-linear problems. A non-linear problem is a problem that is so abstract that it cannot easily be solved by a computer, for example stowage problems, there are simply too many factors for a computer to process.”

Stowage is complex problem that is little understood outside the world of stowage coordinators. Utilization, terminal productivity and stowage quality are mainly affected by three main areas:

1) Forecast Quality

2) Port Rotation

3) Coordinator Ability

1) Forecast Quality

The accuracy of our forecasts is not up to the level that is required for creating an optimal stowage, both coordinators and automated systems (such as SHOP - Stowage Handling Optimization Program) are adversely affected by this. Every stow requires numerous decisions to be taken that will have an effect, either positive or negative, on later ports and the overall utilization of a vessel. If, for example, the forecast quality were to be 95% accurate then more correct decisions could be made. When the forecast quality is sub-optimal, decisions have to be taken that may prove to be incorrect but a coordinator (or system) has no way of knowing this at the time. Accurate forecasting would give the planner the ability to pre-plan the ports ahead in the rotation to a much greater level of accuracy than is currently possible. If we know what is coming, we can plan for it. When we do not have a clear picture of the road ahead, the result is having to keep as many options open as is possible and this can lead to an overall deterioration in the perceived stowage quality. Essentially, the stowage coordinator has to plan for a series of “what-if” scenarios because we cannot rely totally on a forecast.

2) Port Rotation

The complexities of a network drives the complexities of the stowages to a large degree. When the port rotation is increased above 3 or 4 ports per region, the number of possible stowage outcomes increases exponentially. This dramatically increases the opportunities for incorrect decisions to be made. The fewer the ports in a rotation, the more consolidated the cargo will become for each port. With the same volume of containers to be dealt and a smaller number of stowages, it becomes possible to utilize a vessel better with fewer restows. Essentially, the more ports we have to deal with, the greater the chance there is for something to go wrong.

3) Coordinator Ability

Without a doubt, the experience, background and training of coordinators has an impact on stowage quality and vessel utilization but this cannot be viewed in isolation. The way vessels are utilized and the effects of the stowages on port productivity can be traced back to the two other areas discussed, Forecast Quality and Port Rotation. Increasing the level of stowage coordinator training alone will not solve the challenges that a stowage department faces.

Stowage Quality

This is a difficult area to define because a lot of what makes a stowage good depends on what the requirements are at the time. There is no generic definition of a good stowage.

What was the coordinator trying to achieve with this stowage? What were the primary operational and commercial requirements at the time? Was it crane split, reefers, BBLK, IMO, OOG, reduced ballast, optimal trim etc?

What would be the definition of a good stowage on one particular vessel in a port on a service would not necessarily make a good stow on a different vessel but on the same service and port next week. The requirements and containers to be loaded and discharged change from stowage to stowage.

Virtually everything in stowage is a trade-off. Because of long port rotations, there is a loss of flexibility. To compensate for this and to provide higher crane intensities, we have to divide the vessel into more sections. By doing this there is a loss of crane and terminal productivity. We could, for example, reduce crane intensities to gain higher terminal productivities through more consolidation of the cargo. But if we did that then we would be unable to deliver the number of cranes required for the full voyage. Some ports would have to deploy fewer cranes which would result in a decrease in schedule reliability and higher fuel costs.

Stowage Coordinators have to continually work to balance the commercial and operational requirements of the organization and they are not always going to be compatible with one another.