A key issue for system safety is to identify and understand the factors that affect human performance in relation to the technical systems being operated and the environment in which work is taking place. This task should start from the early stage of the SCC definition and should refine its results as the design progresses, giving the necessary retrofits at different levels: from changes in concept defini­tion to requirement modifications/extensions. Human error analysis should also be integrated with the traditional engineering approach during the phases of the overall safety lifecycle. The activities under this domain should, at least, consider the fol­lowing key aspects (ATOMOS, 1998):

• Error sources—The use of the SCC in general, or of one of its subsystems, which is likely to lead to error; for example, long, complex procedures for simple operations.

• Use behaviour—Misuse and abuse of subsystems that have safety implica­tions for the user. For example, inadequate materials, skill and attitude of the system’s operator, ergonomic design, and the interpretation of information received are all aspects that have a direct influence on checking human error.

• Surroundings—External environmental conditions that have safety impli­cations for the SCC user or third parties involved in ship’s operations, e. g., piracy, extreme weather, dangerous cargo (chemical, biological, explosive, and flammable).