Shifting role for human factors in an ‘unmanned’ era

Human factors practitioners (HFPs) play many different roles in the design, creation, operation and maintenance of engineered systems. Less well known are the methods which are aimed at helping with the early stages of design, which are more systems-oriented and often involve questions of the concept of operation in which the engineered system will be fielded. Emerging from the field of cognitive engineering, these methods, including simulation, cognitive work analysis, cognitive task analyses and hierarchical task analysis, will be important as autonomous systems become increasingly capable. Even the most capable systems will continue to interact with humans, and it is at these interfaces between humans and engineered systems that HFP will continue to be needed. This paper describes recent work to leverage these methods to inform concepts of operation in aviation and space, machine learning algorithms and goal-oriented human–machine collaboration.     

The French-speaking ergonomists' approach to work activity: cross-influences of field intervention and conceptual models

French-speaking ergonomists generally consider the concept of activity to be central in their approach to work and to changing it. However, their understanding of the term developed in a specific context, combining the influence of Soviet psychology with that of other forms of thinking already developed in France. Since then, the notion has received considerable input. The concept of activity as it has been developed in French-speaking countries (and thereafter in others like Brazil as it has spread) is not exactly identical to that developed by Engeström, even if there are obviously many common points. The aim of this article is not to make a systematic international comparison of approaches all referring to the concept of activity. Rather, the author's objective is limited to explaining the emergence of the concept as it is taught in France with its theoretical and methodological consequences. The reader should, therefore, not be unduly surprised by the focus on French-speaking ergonomists; this is not testimony to ignorance of the international literature, but constitutes the specific nature of this essay. If other authors attempt a similar clarification of thought at a later date, it will be easier for the international ergonomic community to distinguish the resemblances and differences between the approaches on an international level.     

A systems analysis approach to solving office work system health and performance problems

This paper describes a systems analysis approach to human performance in office work systems. The approach, integrating both micro- and macroergonomic aspects, provides a process for more comprehensive, systematic solutions. This systems approach is designed to assess office workers' performance and effectiveness problems within technology intensive office work environments and provide realistic solutions for improving performance. The approach incorporates micro- and macroergonomic factors to adequately address the performance and stress and health-related problems associated with modern office work systems. The seven step approach consists of: defining the problems; setting the objectives and developing alternatives; modelling alternatives; evaluating alternatives; selecting an alternative; planning for implementation; and evaluation, feedback and modification. A detailed schematic presentation of these steps is provided. Solutions or alternatives are proposed to minimize the identified problem factors and to improve performance and the quality of work life.     

Using cognitive work analysis to describe the role of UAVs in military operations

Advances in uninhabited vehicle design have resulted in increased levels of autonomy – allowing command to be communicated at high levels of abstraction, rather than detailed control. The resultant change in interaction requirements has obvious implications for the redesign of current operator interfaces. Furthermore, it allows the organisation design to be reconsidered. A reduction in the requirement for human involvement could allow control to be passed from dedicated remote controllers to actors involved directly with local tasks. This offers a number of potential benefits. Those involved with the task directly may have a greater situational understanding, allowing them to make faster decisions that are more informed. Furthermore, dynamic function allocation would allow assets to be shared, with command passed to the actor best placed to make decisions. This article uses a systemic approach, cognitive work analysis (CWA), to explore the constraints within military air operations, and derive systemic information requirements. The understanding developed from the CWA of the military air operations domain constraints is used to postulate the implications of introducing unmanned air vehicles. The example illustrates how the constraint-based approach can form the basis for considering system change.     

Using cognitive work analysis to explore system flexibility

The presented work describes a structured approach for identifying flexible working practices in complex socio-technical systems; further, it presents a framework for the elicitation of design changes capable of increasing system adaptability. The proposed approach uses the first three phases of the cognitive work analysis framework: work domain analysis; control task analysis; and strategies analysis. Functions are extracted from an abstraction hierarchy; these are then explored in a number of different situations using a contextual activity template. These functions are then explored in greater detail with the strategies analysis phase. The contextual activity template is used to identify situations where functions are unable to perform; in order to increase the flexibility of the system, new strategies are then proposed and represented in strategies analyses flow diagrams. To communicate the approach, it is introduced using the familiar, domestic domain of an ‘Apple iPod’. The paper presents a structured approach based upon cognitive work analysis for exploring system flexibility. The case study presented, an Apple iPod, shows how design changes to the system can be informed by this approach. This paper takes an existing approach and clarifies the link between analysis and design.     

Hierarchical task analysis vs. cognitive work analysis: comparison of theory,methodology and contribution to system design

The cognitive work analysis framework continues to attract increasing attention from the human factors and ergonomics community. Conversely, hierarchical task analysis has been, and remains, the most popular of all human factors and ergonomics methods. This article compares the two approaches in terms of their theoretical underpinning, methodological approach and potential contributions to system design and evaluation. To do this, recent analyses, involving both approaches, of a military rotary wing mission planning software tool are compared and contrasted in terms of their methodological procedure and analysis outputs. The findings indicate that, despite the very different theoretical and methodological nature of the two approaches, and also the entirely different analyses derived, the two methods provide highly complementary outputs. In conclusion, it is argued that there is benefit in applying both approaches to inform the design and/or evaluation of the same product or system.     

Embracing complexity: a sociotechnical systems approach for the design and evaluation of higher education learning environments

ABSTRACT

Higher education institutions (HEI) have undergone fundamental changes driven by ICT developments, globalisation, and the advent of socio-constructivist pedagogic approaches. As a result, within the UK, capital investment in new and retrofitted facilities has reached a record expenditure. Recent research on user-related evaluations of facilities, particularly in HEI learning spaces, highlights the prevalence of evaluations dominated by reductionist approaches focused on measuring outcomes, on users, such as satisfaction, learning outcomes or engagement. These approaches have a major pitfall, neglecting the complexity of the dynamic relationships between people, spaces, technology, institutional structure and pedagogic practices. In response, this paper aims to propose a shift on current approaches by exploring the application of sociotechnical systems theory to learning space design and evaluation. Amid these, it is argued that Cognitive Work Analysis (CWA) offers promising alternatives to inform design and management of higher education learning spaces. Finally, within the paper, three CWA interventions are proposed and discussed, focusing on how these address previously identified shortcomings of predominant approaches used in HEI learning space design and evaluation.     

Incorporating organizational factors into Probabilistic Risk Assessment (PRA) of complex socio-technical systems: A hybrid technique formalization

This paper is a result of a research with the primary purpose of extending Probabilistic Risk Assessment (PRA) modeling frameworks to include the effects of organizational factors as the deeper, more fundamental causes of accidents and incidents. There have been significant improvements in the sophistication of quantitative methods of safety and risk assessment, but the progress on techniques most suitable for organizational safety risk frameworks has been limited. The focus of this paper is on the choice of “representational schemes” and “techniques.” A methodology for selecting appropriate candidate techniques and their integration in the form of a “hybrid” approach is proposed. Then an example is given through an integration of System Dynamics (SD), Bayesian Belief Network (BBN), Event Sequence Diagram (ESD), and Fault Tree (FT) in order to demonstrate the feasibility and value of hybrid techniques. The proposed hybrid approach integrates deterministic and probabilistic modeling perspectives, and provides a flexible risk management tool for complex socio-technical systems. An application of the hybrid technique is provided in the aviation safety domain, focusing on airline maintenance systems. The example demonstrates how the hybrid method can be used to analyze the dynamic effects of organizational factors on system risk.     

Multi-class queueing models for performance analysis of computer systems

Queueing models, networks of queues in particular, have been found especially useful for estimating the performance of computer systems. Networks of queues with multiple customer classes provide a flexible framework for modelling computer systems, where a rich set of analytical results and techniques are available. When because of the complexity of the system being modelled the analytical results cannot be applied directly, they often point to fairly accurate approximation schemes. In this paper, we present a brief survey of some of the important results and techniques from the theory of multi-class queueing networks. We also present a case study to illustrate how these results and techniques are used in a real-life situation where many of the modelling constraints are violated.     

Dynamics in socio-technical systems: Typology of change processes and contrasting case studies

This paper deals with fundamental change processes in socio-technical systems. It offers a typology of changes based on a multi-level perspective of innovation. Three types of change processes are identified: reproduction, transformation and transition. ‘Reproduction’ refers to incremental change along existing trajectories. ‘Transformation’ refers to a change in the direction of trajectories, related to a change in rules that guide innovative action. ‘Transition’ refers to a discontinuous shift to a new trajectory and system. Using the multi-level perspective, the underlying mechanisms of these change processes are identified. The transformation and transition processes are empirically illustrated by two contrasting case studies: the hygienic transition from cesspools to integrated sewer systems (1870–1930) and the transformation in waste management (1960–2000) in the Netherlands.     

Injury causation in the great outdoors: A systems analysis of led outdoor activity injury incidents

Despite calls for a systems approach to assessing and preventing injurious incidents within the led outdoor activity domain, applications of systems analysis frameworks to the analysis of incident data have been sparse. This article presents an analysis of 1014 led outdoor activity injury and near miss incidents whereby a systems-based risk management framework was used to classify the contributing factors involved across six levels of the led outdoor activity ‘system’. The analysis identified causal factors across all levels of the led outdoor activity system, demonstrating the framework's utility for accident analysis efforts in the led outdoor activity injury domain. In addition, issues associated with the current data collection framework that potentially limited the identification of contributing factors outside of the individuals, equipment, and environment involved were identified. In closing, the requirement for new and improved data systems to be underpinned by the systems philosophy and new models of led outdoor activity accident causation is discussed.     

Fuzzy-logic-based network for complex systems risk assessment: Application to ship performance analysis

In this paper, a new interpretation of intuitionistic fuzzy sets in the advanced framework of the Dempster–Shafer theory of evidence is extended to monitor safety-critical systems’ performance. Not only is the proposed approach more effective, but it also takes into account the fuzzy rules that deal with imperfect knowledge/information and, therefore, is different from the classical Takagi–Sugeno fuzzy system, which assumes that the rule (the knowledge) is perfect. We provide an analytical solution to the practical and important problem of the conceptual probabilistic approach for formal ship safety assessment using the fuzzy set theory that involves uncertainties associated with the reliability input data. Thus, the overall safety of the ship engine is investigated as an object of risk analysis using the fuzzy mapping structure, which considers uncertainty and partial truth in the input–output mapping. The proposed method integrates direct evidence of the frame of discernment and is demonstrated through references to examples where fuzzy set models are informative. These simple applications illustrate how to assess the conflict of sensor information fusion for a sufficient cooling power system of vessels under extreme operation conditions. It was found that propulsion engine safety systems are not only a function of many environmental and operation profiles but are also dynamic and complex.     

Routes to failure: analysis of 41 civil aviation accidents from the Republic of China using the human factors analysis and classification system

The human factors analysis and classification system (HFACS) is based upon Reason's organizational model of human error. HFACS was developed as an analytical framework for the investigation of the role of human error in aviation accidents, however, there is little empirical work formally describing the relationship between the components in the model. This research analyses 41 civil aviation accidents occurring to aircraft registered in the Republic of China (ROC) between 1999 and 2006 using the HFACS framework. The results show statistically significant relationships between errors at the operational level and organizational inadequacies at both the immediately adjacent level (preconditions for unsafe acts) and higher levels in the organization (unsafe supervision and organizational influences). The pattern of the 'routes to failure' observed in the data from this analysis of civil aircraft accidents show great similarities to that observed in the analysis of military accidents. This research lends further support to Reason's model that suggests that active failures are promoted by latent conditions in the organization. Statistical relationships linking fallible decisions in upper management levels were found to directly affect supervisory practices, thereby creating the psychological preconditions for unsafe acts and hence indirectly impairing the performance of pilots, ultimately leading to accidents.     

Agent-based modelling of movement rules in DRC systems for volume flexibility: human factors and technical performance

This research applies agent-based modelling (ABM) to study volume flexibility in a dual resource constrained (DRC) assembly flow shop environment. The simulation experiment evaluated system and human effects of varying DRC system staffing levels according to design (i.e., workforce, distance and buffer capacity), sensitivity (i.e. coefficient of variation) and operating (i.e. when rule and where rule) factors. Results showed that the rule by which workers are assigned to workstations affects WIP and flow time performances more than production rates. Furthermore per-worker productivity was found to increase, compared to the fully staffed system, particularly where the downstream movement rule was applied. Using the downstream rule when changing stations after completing current tasks reduced flow time (?15%) and WIP (?10%). If another where rule is chosen then it may be preferable for workers to move only after completing all jobs in the station (decentralised rule). For utilisation rates and mean hourly switching of work (human effects), the model shows complex relationships depending on almost all evaluated factors. The novel ABM approach used here enabled the evaluation of emergent system behaviours and showed potential to help firms understand both human and performance effects of operational choices in efforts to achieve volume flexibility.     

Sensitivity of direct metal laser sintering Maraging steel fatigue strength to build orientation and allowance for machining

This work deals with the effect of build orientation and of allowance for machining on DMLS‐produced Maraging Steel MS1. The experimental results, arranged by tools of Design of Experiment, have been statistically processed and compared. The outcomes were that, probably due to effect of the thermal treatment, machining, and material properties, the aforementioned factors do not have a significant impact on the fatigue response. This made it possible to work out a global curve that accounts for all the results, consisting in a high amount of data points. This can be regarded as one of the most complete and reliable fatigue models in the current literature. Fractographic and micrographic studies have been performed as well, to individuate the crack initiation points, usually located at subsurface porosities, and to investigate the location of internal inclusions and the actual martensitic microstructure along the stacking direction and on the build plane.     

Application of Human Factors Analysis and Classification System (HFACS) to UK rail safety of the line incidents

Minor safety incidents on the railway cause disruption, and may be indicators of more serious safety risks. The following paper aimed to gain an understanding of the relationship between active and latent factors, and particular causal paths for these types of incidents by using the Human Factors Analysis and Classification System (HFACS) to examine rail industry incident reports investigating such events. 78 reports across 5 types of incident were reviewed by two authors and cross-referenced for interrater reliability using the index of concordance. The results indicate that the reports were strongly focused on active failures, particularly those associated with work-related distraction and environmental factors. Few latent factors were presented in the reports. Different causal pathways emerged for memory failures for events such a failure to call at stations, and attentional failures which were more often associated with signals passed at danger. The study highlights a need for the rail industry to look more closely at latent factors at the supervisory and organisational levels when investigating minor safety of the line incidents. The results also strongly suggest the importance of a new factor – operational environment – that captures unexpected and non-routine operating conditions which have a risk of distracting the driver. Finally, the study provides further demonstration of the utility of HFACS to the rail industry, and of the usefulness of the index of concordance measure of interrater reliability.     

小波变换在电力系统谐波检测中的应用

将小波变换方法应用于电力系统谐波检测中，用仿真算例说明该方法具有一定的有效性和可行性；用不同的小波函数进行了基频分量提取，给出了误差比较结果，初步分析了小波变换用于谐波检测时产生误差的主要原因．