Human factors and workload: why crews can't always follow optimisation

Bridge teams are stretched thin: they manage navigation, safety, communication, regulatory reporting and a growing volume of digital alerts. This insight looks at how crew workload and alarm fatigue create a hard ceiling on what manual optimisation can achieve, and why the next step in efficiency may need to come from automation that supports, rather than burdens, the people on board.

As in much of maritime generally, people are a central part of closing the execution gap. Bridge teams operate in busy, stressful environments. They are responsible for navigation, collision avoidance, communication with shore teams, safety procedures, reporting requirements, and regulatory compliance.

Highlighting the pressures crews can face (as well as the aforementioned challenges with data consistency), Prateek Rana, Maritime Decarbonisation Consultant at Siglar Carbon, said, “it is often one junior engineer writing everything down and sending the same data to multiple stakeholders in different formats.” The duplication of effort illustrates how inefficient processes can be and how ingrained they are within workflows.

With all these factors competing for attention, the IMO has also recognised fatigue as a serious issue that can affect performance and decision-making at sea. Recent research has also highlighted how the growing volume of digital alerts and alarms onboard vessels is adding to crew workload.

This pressure on the crew is often compounded by the expectations to deliver results from optimisation tools. As Prateek Rana, Maritime Decarbonisation Consultant at Siglar Carbon, noted, “it is stressful; if tools don’t match expectations, the first people to face the blame are the crew.”

When alarms are noisy, badly prioritised, or hard to manage, they get in the way of clear communication and good decisions. “We have a saying in shipping: safety first. The crew needs to maintain situational awareness before moving on to other topics such as energy efficiency and optimisation. We have to make systems that are much more user-friendly. Currently, they are not user-friendly, and they provide the information in a manner which is not optimised”, stressed Christos Papadopoulos, Energy and Environmental Engineer at a large global shipping company.

A 2026 study by Lloyd’s Register analysing more than 40 million alarm events across 11 operational vessels found that many vessels generate thousands, and sometimes tens of thousands, of alarms daily. Many of these alarms provide ambiguous levels of operational value and ultimately just contribute to “alarm fatigue”, disrupted rest, and reduced crew trust in onboard systems which are designed to support safety.

Given this operating context, speed optimisation adds another layer of complexity and yet another task on a growing list of crew expectations. Following constantly updated propulsion recommendations requires the crew to closely monitor tools and make regular adjustments.

Engine operating limits, restricted RPM ranges, or other technical constraints can further complicate this process. While each manual adjustment seems quick in isolation, in the context of crew workload and the number of required adjustments, the time spent turning the tools’ advice into reality begins to snowball.

There is a practical limit to how far efficiency can be improved through manual adjustments alone, especially given regulatory requirements that increase pressure on operators to demonstrate consistent performance.

Survey respondents reinforced this, with 54% identifying human or crew behaviours as the main limiting factor, while 63% said operational pressure is a moderate or major challenge when it comes to following optimisation recommendations in practice.

While the majority of operators are still in the exploration stage of speed optimisation and have not yet reached this limit, this creates a challenge for those who are already seeing the unrealised potential on a daily basis.

These players realise that achieving improved levels of optimisation might require more than just better recommendations and more crew education. It might also require automation tools which help crews apply recommendations more consistently in daily operations.

Download our latest report 'Precision in motion' to find out all about next steps and best practices in efficiency.