Advantages of shift changeovers with meetings: ergonomic analysis of shift supervisors' activity in aircraft building

Good shift changeovers contribute to ensuring continuity and reliability in shift work. In situations where production is not maintained 24 h a day, changeovers with meetings (SCM) between the two work teams (written plus oral face-to-face handovers) alternate with changeovers without meetings (SCnM; written handovers only). An ergonomic work analysis on an aircraft assembly line showed that (1) incoming and outgoing operators met during the overlap time allotted by the company, and (2) the content of the exchanges was richer for SCMs than for SCnMs. SCMs enabled the operators to pass on and process more aspects of their work than SCnMs did. SCMs also allowed incoming operators to validate their predictions, and enabled both outgoing and incoming operators to update their mental models and work together on peripheral aspects of the technical process over a greater time span. The findings highlight the importance of allowing overlap time in shift work.     

Safety implications of cultural and cognitive issues in nuclear power plant operation

This research project was designed to investigate cultural and cognitive issues related to the work of nuclear power plant operators during their time on the job in the control room and during simulator training (emergency situations), in order to show how these issues impact on plant safety. The modeling of the operators work deals with the use of operational procedures, the constant changes in the focus of attention and the dynamics of the conflicting activities. The paper focuses on the relationships between the courses of action of the different operators and the constraints imposed by their working environment. It shows that the safety implications of the control room operators' cognitive and cultural issues go far beyond the formal organizational constructs usually implied. Our findings indicate that the competence required for the operators are concerned with developing the possibility of constructing situation awareness, managing conflicts, gaps and time problems created by ongoing task procedures, and dealing with distractions, developing skills for collaborative work.     

Reasoning and knowledge of nuclear power plant operators in case of accidents

This paper presents the results of an ergonomics analysis of the work activities of nuclear power plant operators. It focuses on cognitive activity during simulated accidents. Qualitative aspects of this activity are described, which include operators' knowledge, diagnoses, goals, situation ranking and procedure management. The results show that successful emergency operation depends on a combination of adherence to procedures and specific operator competence.     

Design and Evaluation of a Team Mutual Awareness Toolkit for Digital Interfaces of Nuclear Power Plant Context

In the teamwork of nuclear power plants (NPPs), the maintenance of mutual awareness enables the operators to have an up-to-the-moment understanding of each other’s work and makes the collaboration more efficient. Providing interface support for mutual awareness is proven to be an effective way to enhance the operators’ mutual awareness in digital systems. What mutual awareness-relevant information to provide and how to present the information on the display are two questions worth studying. This research focused on the above two questions and provided a newly designed mutual awareness toolkit on the context of digital interfaces in NPPs. The usability of the designed toolkit was evaluated through a laboratory experiment. The influence of the mutual awareness toolkit on team performance and its interaction effect with task complexity was further examined under incident scenarios. The results showed that the designed mutual awareness toolkit improved the operators’ mutual awareness, while it did not decrease their individual situation awareness (SA) or impose extra mental workloads. In team diagnosis tasks, the teams using the mutual awareness toolkit more thoroughly discussed the incident scenarios and identified more key points of the incidents. The diagnosis correctness, perhaps moderated by other factors besides mutual awareness, was not significantly improved.     

Coordinating multi‐level cognitive assistance and incorporating dynamic confidence information in driver‐vehicle interfaces

Automation technologies have now been widely introduced into many aspects of human–machine collaboration. Most automated systems, however, are still far from perfect in performing assistive duties for their operators. This situation can lead to chaotic assistance, which can easily cause cognitive confusion and performance degradation among operators. This article discusses how to coordinate multiple types of assistance that have different levels of cognitive intrusiveness. To improve the cognitive adaptability of operators, dynamic confidence information is presented on the interactive interface to indicate the likelihood of the correctness of such assistance. Multiple types of assistance are then presented at different moments to match human‐cognitive‐processing stages and eventually to attain a coordinated status. In a car‐following driving experiment, the drivers' responses to multiple types of assistance with dynamic confidence information were investigated. The coordinated assistance successfully enhanced the drivers' driving performance and the human–machine relationship. This method can be further generalized to improve human–machine collaboration in many industrial automation systems that still require human operators. © 2012 Wiley Periodicals, Inc.     

Team situation assessment and information distribution

Described is the cooperative work of constructing team situation awareness within two teams of a military command and control unit. Specifically discussed is how the distributed cognitive and cooperative work of decision-making of the two teams is structured. The situation enabled two different ways of distributing information within the team: one serial and one parallel. One team chose the parallel information transfer, the other the serial one. Discussed is the interaction patterns that emerge in the respective teams and their consequences for situation assessment and situation awareness. The differences are then discussed in terms of means of sharing information. Some hypotheses for future research are also offered.     

Team situation assessment and information distribution

Described is the cooperative work of constructing team situation awareness within two teams of a military command and control unit. Specifically discussed is how the distributed cognitive and cooperative work of decision-making of the two teams is structured. The situation enabled two different ways of distributing information within the team: one serial and one parallel. One team chose the parallel information transfer, the other the serial one. Discussed is the interaction patterns that emerge in the respective teams and their consequences for situation assessment and situation awareness. The differences are then discussed in terms of means of sharing information. Some hypotheses for future research are also offered.     

Was Three Mile Island a ‘Normal Accident’?

Perrow’s normal accident theory suggests that some major accidents are inevitable for technological reasons. An alternative approach explains major accidents as resulting from management failures, particularly in relation to the communication of information. This latter theory has been shown to be applicable to a wide variety of disasters. By contrast, Perrow’s theory seems to be applicable to relatively few accidents, the exemplar case being the Three Mile Island nuclear power station accident in the U.S. in 1979. This article re‐examines Three Mile Island. It shows that this was not a normal accident in Perrow’s sense and is readily explicable in terms of management failures. The article also notes that Perrow’s theory is motivated by a desire to shift blame away from front line operators and that the alternative approach does this equally well.     

Operators in Process Industry: Interaction with Wearable Computers

Field operators need access to and interaction with more information than is available today during field operations. Wearable computers can provide relevant information with hands-free interaction techniques to support work tasks in the field. Potential implications of introducing wearable computers are collaboration, information overload, situation awareness and social relationships. Interaction techniques between humans are natural and well known and include voice, gestures, eye movements and biopotentials. Voice is a promising interaction technique for wearable computers, assuming improvements for rough and noisy environments. Wearable computers may change the roles and responsibilities while providing extended support for communication and collaboration. Field operators will be better prepared to prevent failures and secure quality. Control room operators will perform more administrative and management tasks. Correspondence and offprint requests to: C. Skourup, ABB AS, Corporate Research Center, Bergerveien 12, PO Box 90, N-1375 Billingstad, Norway. Email: charlotte.skourup@no.abb.com     

Investigating interactions among vital variables affecting situation awareness based on Fuzzy DEMATEL method

In many accident reports, failure in situation awareness is mentioned as one of the immediate causes of those accidents. Accordingly, the identification of variables affecting situation awareness and their interactions are key factors in preventing accidents. This study aims to identify interactions among the most important individual, situational, and organizational variables affecting situation awareness in industrial workplaces. Using Fuzzy Delphi and Fuzzy DEMATEL methods, this study was conducted based on the data collected from experts’ judgments. The results show that organizational variables and some individual variables are the critical factors affecting situation awareness, and their effect is directly or indirectly created by situational and individual variables. The results of the study can be used to design proper guidelines for industry managers and employers to improve safety performance in the workplace; in addition, the findings of the study can be employed to design future studies to model the predictive power of variables affecting situation awareness in different work environments.     

Situation awareness assessment in critical driving situations at intersections by task and human error analysis

The rapid development of sensor and tracking technology enables deployment of new Advanced Driver Assistance Systems (ADAS) that support the driver not just on highways but in urban areas as well. Intersections particularly present critical traffic scenarios where almost 35% of accidents occur, partially due to the present lack of in‐depth research about human errors and their determinants. The first step in ergonomic design of ADAS is to identify the specific situations in which drivers require support. To contribute to identification of such spots, situation awareness of 20 drivers in four critical intersection scenarios was explored. The study was conducted in the fixed‐base driving simulator. The applied approach consisted of assessing drivers' expectations and mental workload and of comparing theoretically correct cognitive behavior to experimentally collected data. Intersection scenarios were divided into five segments, and for each segment a task analysis was made. The study has shown that the driving simulator environment can be successfully deployed to provoke and explore various driver errors. The results have revealed that, in scenarios in which information is objectively missing, the majority of errors happened because the drivers had inaccurate mental models of particular scenarios. To the contrary, in the complex scenario the major cause of accidents was information overload. Furthermore, the task analysis disclosed applicable areas of intersection assistance. © 2010 Wiley Periodicals, Inc.     

Influence of shift work in process industry on workers' occupational health,productivity, and family and social life: An ergonomic approach

Shift work is a major feature of modern work practices. It involves working at times considered unconventional for most workers, such as at night. Although the community often benefits from such work practices, shift work can be hazardous for both the workers and the community. There are increased risks for accidents and errors, increased sleepiness and fatigue due to difficulties sleeping, increased health problems, and disruptions to family and social life. More shift workers complained of sleep disturbance, poor sleep quality, tiredness at awakening, and sleepiness in work than did non‐shift workers. More shift workers also complained of gastrointestinal disturbances than did non‐shift workers. The aim of this article is to provide general information on shift work, work schedules, and the effects of work schedules on sleep, fatigue, performance, the health of the human operator, and productivity. © 2010 Wiley Periodicals, Inc.     

Normal people working in normal organizations with normal equipment: System safety and cognition in a mid-air collision

A fundamental challenge in improving the safety of complex systems is to understand how accidents emerge in normal working situations, with equipment functioning normally in normally structured organizations. We present a field study of the en route mid-air collision between a commercial carrier and an executive jet, in the clear afternoon Amazon sky in which 154 people lost their lives, that illustrates one response to this challenge. Our focus was on how and why the several safety barriers of a well structured air traffic system melted down enabling the occurrence of this tragedy, without any catastrophic component failure, and in a situation where everything was functioning normally. We identify strong consistencies and feedbacks regarding factors of system day-to-day functioning that made monitoring and awareness difficult, and the cognitive strategies that operators have developed to deal with overall system behavior. These findings emphasize the active problem-solving behavior needed in air traffic control work, and highlight how the day-to-day functioning of the system can jeopardize such behavior. An immediate consequence is that safety managers and engineers should review their traditional safety approach and accident models based on equipment failure probability, linear combinations of failures, rules and procedures, and human errors, to deal with complex patterns of coincidence possibilities, unexpected links, resonance among system functions and activities, and system cognition.     

Improving situation awareness in crisis response teams: An experimental analysis of enriched information and centralized coordination

In responding to an emergency, the actions of emergency response teams critically depend upon the situation awareness the team members have acquired. Situation awareness, and the design of systems to support it, has been a focus in recent emergency management research. In this paper, we introduce two interventions to the core processes of information processing and information sharing in emergency response teams to analyze their effect on the teams’ situation awareness: (1) we enrich raw incoming information by adding a summary of the information received, and (2) we channel all incoming information to a central coordinator who then decides upon further distribution within the team. The effect of both interventions is investigated through a controlled experiment with experienced professional responders. Our results show distinctly different effects for information enrichment and centralization, both for the teams and for the coordinators within the team. While the interaction effects of both conditions cannot be discerned, it is apparent that processing non-enriched information and non-centralized information sharing leads to a worse overall team situation awareness. Our work suggests several implications for the design of emergency response management information systems.     

There is more to monitoring a nuclear power plant than meets the eye

A fundamental challenge in studying cognitive systems in context is how to move from the specific work setting studied to a more general understanding of distributed cognitive work and how to support it. We present a series of cognitive field studies that illustrate one response to this challenge. Our focus was on how nuclear power plant (NPP) operators monitor plant state during normal operating conditions. We studied operators at two NPPs with different control room interfaces. We identified strong consistencies with respect to factors that made monitoring difficult and the strategies that operators have developed to facilitate monitoring. We found that what makes monitoring difficult is not the need to identify subtle abnormal indications against a quiescent background, but rather the need to identify and pursue relevant findings against a noisy background. Operators devised proactive strategies to make important information more salient or reduce meaningless change, create new information, and off-load some cognitive processing onto the interface. These findings emphasize the active problem-solving nature of monitoring, and highlight the use of strategies for knowledge-driven monitoring and the proactive adaptation of the interface to support monitoring. Potential applications of this research include control room design for process control and alarm systems and user interfaces for complex systems.     

Handling effective communication to support awareness in rescue operations

Efficient rescue operations require a high level of situation awareness amongst decision‐makers and first responders for the purpose of achieving operations successfully and reducing losses. Moreover, a common operational picture between involved actors is required in order to support decision‐making. Therefore, different organisations and agencies have to collaborate, cooperate, and coordinate their actions with each other. Hence, effective interactions and communications between participants are vital to fulfil these essential needs. However, emergency actors still lack backing to exchange information effectively and ensure a common operational picture in order to reach shared situational awareness. For this reason, we aim to develop and implement Rescue MODES, a communication system oriented to support situation awareness amongst French emergency actors in rescue operations. In this paper, we examine and analyse actors’ activities and interactions, so that the system will be based on the real needs of actors. We start by studying and modelling the communications, interactions, and information flow. This modelling is based on an application ontology. Then, we define requirements for good communication in these operations and present some existing systems in France and how each system responds to these requirements.     

Automation transparency: implications of uncertainty communication for human-automation interaction and interfaces

Operators of highly automated driving systems may exhibit behaviour characteristic for overtrust issues due to an insufficient awareness of automation fallibility. Consequently, situation awareness in critical situations is reduced and safe driving performance following emergency takeovers is impeded. A driving simulator study was used to assess the impact of dynamically communicating system uncertainties on monitoring, trust, workload, takeovers, and physiological responses. The uncertainty information was conveyed visually using a stylised heart beat combined with a numerical display and users were engaged in a visual search task. Multilevel analysis results suggest that uncertainty communication helps operators calibrate their trust and gain situation awareness prior to critical situations, resulting in safer takeovers. In addition, eye tracking data indicate that operators can adjust their gaze behaviour in correspondence with the level of uncertainty. However, conveying uncertainties using a visual display significantly increases operator workload and impedes users in the execution of non-driving related tasks.

Practitioner Summary: This article illustrates how the communication of system uncertainty information helps operators calibrate their trust in automation and, consequently, gain situation awareness. Multilevel analysis results of a driving simulator study affirm the benefits for trust calibration and highlight that operators adjust their behaviour according to multiple uncertainty levels.     

Robot Teams for Intervention in Confined and Structured Environments

Safety, security, and rescue robotics can be extremely useful in emergency scenarios such as mining accidents or tunnel collapses where robot teams can be used to carry out cooperative exploration, intervention, or logistic missions. Deploying a multirobot team in such confined environments poses multiple challenges that involve task planning, motion planning, localization and mapping, safe navigation, coordination, and communications among all the robots. To complete their mission, robots have to be able to move in the environment with full autonomy while at the same time maintaining communication among themselves and with their human operators to accomplish team collaboration. Guaranteeing connectivity enables robots to explicitly exchange information needed in the execution of collaborative tasks and allows operators to monitor and teleoperate the robots and receive information about the environment. In this work, we present a system that integrates several research aspects to achieve a real exploration exercise in a tunnel using a robot team. These aspects are as follows: deployment planning, semantic feature recognition, multirobot navigation, localization, map building, and real‐time communications. Two experimental scenarios have been used for the assessment of the system. The first is the Spanish Santa Marta mine, a large mazelike environment selected for its complexity for all the tasks involved. The second is the Spanish‐French Somport tunnel, an old railway between Spain and France through the Central Pyrenees, used to carry out the real‐world experiments. The latter is a simpler scenario, but it serves to highlight the real communication issues.     

Shiftwork and work injuries in an iron and steel mill

A study on work injuries that occurred over a five-year period was conducted in an iron and steel mill employing over 1000 workers. Of all the 921 injuries which required more than one day's sick leave, over 40% (383 cases) happened during the morning shift (0700-1500 hours), 210 cases occurred in the afternoon shift (1500-2300 hours) and only 150 cases were reported during the night shift. There were two injury peaks throughout the day, one at mid-morning (between 0900 and 1000 hours) and the other towards the mid-afternoon (1400-1500 hours). It was observed that hand injuries were more common during the morning and afternoon shifts and foot injuries normally occurred at night. 'Fall' was one of the main causes of accidents at night, whereas 'struck by' heavy objects and 'burn' were more common during the day. Although there were more accidents during the morning and afternoon shifts, work injuries which occurred at night generally required a longer duration of sick leave. This suggests that accidents which happened at night were more serious. It is believed that the work habits, shift systems and work environment have a substantial influence on these accidents.