View non-flash version
April 2012 www.sname.org/sname/mt and collisions in which crewmembers were engaged in making mobile telephone calls, using laptop computers to communicate with the oce ashore or to make Skype calls, and watching television coverage, usually of sporting events. Add to that list the pressure to deal with electronic paperwork during periods of watchkeeping, and the opportu- nity for distraction through engagement with technology is far greater than in former times. Of course, distraction from the task at hand is a common reality in most workplaces, although the outcome is usually ineciency rather than tragedy. e responsibility for controlling distraction in the workplace remains an issue for management. e prob- lem is that the evidence from recent marine incidents is that the local management is the principal actor who is being distracted from the task by technology that is readily available, and usually without the control of more senior management. It is unclear how widespread the use of potentially absorbing non-essential devices during watchkeeping periods has become. However, it is evident that watchkeepers do become distracted while using equipment that does form part of the essential ship systems, using functions that are available but not immediately essen- tial for operations. Usability and dependability Two key aspects of systems design have a profound a ect on the interaction between people and hardware. e rst is usability, which is in e ect the quality attributed to any artifact that makes it usable, for the intended purpose, by the average user. For any mod- ern ship, this involves many aspects, from the placing of equipment so that it is within easy reach through to the provision of clear information on visual displays. e physical ergonomic criteria are well known, although there are still cases where designers place controls beyond normal comfortable reach. The more pressing problem has been cre- ated by the widespread adoption of digital systems, which provide both considerable advantages in terms of exible and adaptable control functionality and the disadvantages associated with the ease with which too much information can be provided, or provided in a less than helpful display. A case in point is alarm handling, in which the sheer number of alarm channels can present an incompre- hensible picture in a situation where absolute clarity is required if the operator is to make the right decisions. Usability is a function of the ship as designed, constructed, and maintained. It has to be right, because any shortfall that results in the operator and the hardware being incompatible in some way is likely to cause the operator to devise workarounds and shortcuts which can lead to unintended consequences. To achieve a high degree of usability, the designer, the procurer responsible for the definition of require- ments, and the shore-based manager must fully understand the needs of the operating crewmembers. Involvement of the user in the design process, from concept through to detail, is rare, not least because the man- ning arrangement is often not known at the appropriate time. The bridge layout shown in the photo of the small coastal oil tanker Seniority, was developed with direct involvement of the companys seagoing sta , resulting in a design with good usabil- ity. If a system is not usable, the probability of a serious incident is raised. Dependability is a di erent challenge and relates to the degree to which a person relies on a system or piece of equipment. It seems obvious that if an item is critical due to its being relied upon to function correctly, then it must be of the highest integrity. e reliability may be reinforced by the use of duplication with alarm indications to iden- tify failure. However, if a piece of equipment Human behavior is a balance between taking risks and the benet gained by taking those risks. The bridge design for the small oil tanker Seniority was developed with direct involvement of the companys seagoing sta , resulting in a design with good usability. If a system is not usable, the probability of a serious incident is raised.