Macroergonomic Analysis and Design for Improved Safety and Quality Performance

Abstract

Macroergonomics, which emerged historically after sociotechnical systems theory, quality management, and ergonomics, is presented as the basis for a needed integrative methodology. A macroergonomics methodology was presented in some detail to demonstrate how aspects of microergonomics, total quality management (TQM), and sociotechnical systems (STS) can be triangulated in a common approach, in the context of this methodology, quality and safety were presented as 2 of several important performance criteria. To demonstrate aspects of the methodology, 2 case studies were summarized with safety and quality performance results where available. The first case manipulated both personnel and technical factors to achieve a “safety culture” at a nuclear site. The concept of safety culture is defined in INSAG-4 (International Atomic Energy Agency, 1991). as “that assembly of characteristics and attitudes in organizations and individuals which establishes that, as an overriding priority, nuclear plant safety issues receive the attention warranted by their significance.” The second case described a tire manufacturing intervention to improve quality (as defined by Sink and Tuttle, 1989) through joint consideration of technical and social factors. It was suggested that macroergonomics can yield greater performance than can be achieved through ergonomic intervention alone. Whereas case studies help to make the case, more rigorous formative and summative research is needed to refine and validate the proposed methodology respectively.     

Braided River Flow and Invasive Vegetation Dynamics in the Southern Alps, New Zealand

In mountain braided rivers, extreme flow variability, floods and high flow pulses are fundamental elements of natural flow regimes and drivers of floodplain processes, understanding of which is essential for management and restoration. This study evaluated flow dynamics and invasive vegetation characteristics and changes in the Ahuriri River, a free-flowing braided, gravel-bed river in the Southern Alps of New Zealand’s South Island. Sixty-seven flow metrics based on indicators of hydrologic alteration and environmental flow components (extreme low flows, low flows, high flow pulses, small floods and large floods) were analyzed using a 48-year flow record. Changes in the areal cover of floodplain and invasive vegetation classes and patch characteristics over 20 years (1991–2011) were quantified using five sets of aerial photographs, and the correlation between flow metrics and cover changes were evaluated. The river exhibits considerable hydrologic variability characteristic of mountain braided rivers, with large variation in floods and other flow regime metrics. The flow regime, including flood and high flow pulses, has variable effects on floodplain invasive vegetation, and creates dynamic patch mosaics that demonstrate the concepts of a shifting mosaic steady state and biogeomorphic succession. As much as 25 % of the vegetation cover was removed by the largest flood on record (570 m³/s, ~50-year return period), with preferential removal of lupin and less removal of willow. However, most of the vegetation regenerated and spread relatively quickly after floods. Some flow metrics analyzed were highly correlated with vegetation cover, and key metrics included the peak magnitude of the largest flood, flood frequency, and time since the last flood in the interval between photos. These metrics provided a simple multiple regression model of invasive vegetation cover in the aerial photos evaluated. Our analysis of relationships among flow regimes and invasive vegetation cover has implications for braided rivers impacted by hydroelectric power production, where increases in invasive vegetation cover are typically greater than in unimpacted rivers.     

Effects of leadership consideration and structure on employee perceptions of justice and counterproductive work behavior

In this paper, we examine the effects of leadership consideration and structure on two important organizational behavior outcomes: employee perceptions of organizational justice and counterproductive work behavior (CWB). We examine these effects across two studies using multisource data (employees and supervisors in Study 1; employees and coworkers in Study 2). Results reveal that consideration and structure have distinct effects across distributive, procedural, informational, and interpersonal dimensions of justice. Moreover, results suggest that consideration and structure have multiplicative effects on employee CWB. We find the highest levels of CWB among employees of supervisors who exhibit high structure and low consideration. Interestingly, results also suggest that the effects of structure on CWB may be curvilinear (u‐shaped) such that moderate levels of structure are associated with the lowest levels of CWB. We discuss implications for future consideration and structure research as well as managerial practice. Copyright © 2012 John Wiley & Sons, Ltd.     

Water Stress Projections for the Northeastern and Midwestern United States in 2060: Anthropogenic and Ecological Consequences

Future climate and land‐use changes and growing human populations may reduce the abundance of water resources relative to anthropogenic and ecological needs in the Northeast and Midwest (U.S.). We used output from WaSSI, a water accounting model, to assess potential changes between 2010 and 2060 in (1) anthropogenic water stress for watersheds throughout the Northeast and Midwest and (2) native fish species richness (i.e., number of species) for the Upper Mississippi water resource region (UMWRR). Six alternative scenarios of climate change, land‐use change, and human population growth indicated future water supplies will, on average across the region, be adequate to meet anthropogenic demands. Nevertheless, the number of individual watersheds experiencing severe stress (demand > supplies) was projected to increase for most scenarios, and some watersheds were projected to experience severe stress under multiple scenarios. Similarly, we projected declines in fish species richness for UMWRR watersheds and found the number of watersheds with projected declines and the average magnitude of declines varied across scenarios. All watersheds in the UMWRR were projected to experience declines in richness for at least two future scenarios. Many watersheds projected to experience declines in fish species richness were not projected to experience severe anthropogenic water stress, emphasizing the need for multidimensional impact assessments of changing water resources.     

Characterization of Drought in the South Atlantic,United States

Drought has been less extensively characterized in the humid South Atlantic compared to the arid western United States. Our objective was to characterize drought in the South Atlantic and to understand whether drought has become more severe in this region over time. Here we used monthly streamflow to characterize hydrological drought. Hydrological drought occurred when streamflow fell below the 20th percentile over three consecutive months and terminated once streamflow remained above the 20th percentile for three consecutive months. We characterized the frequency, duration, magnitude, and severity of events using the above definition. Significant changes in drought characteristics were tested with Mann‐Kendall over three periods: 1930‐2010, 1930‐1969, and 1970‐2010. We show that 71% of drought events were shorter than six months, while 7% were multiyear events. There was little evidence of trends in drought characteristics to support the claim of drought becoming more severe in the South Atlantic over the 20th Century. The one exception was a significant increase in the joint probability of nearby basins being simultaneously in drought conditions in the southern portion of the study area from 1970 to 2010. While drought characteristics have changed little through time, decreasing average streamflow in non drought periods coupled with increasing water demand provide the context within which recent multiyear drought events have produced significant stress on existing water infrastructure.     

Marine protected areas and local coastal conservation and management in Hong Kong

Abstract

This paper presents as case studies some New Zealand local government sustainable development initiatives in cleaner production and civic building design. From a series of structured interviews with key players, it describes key motivators and demotivators and puts these in the context of behaviour change theory. These enable a set of actions for local government to be developed that, if applied, could result in an advancement of the sustainable development agenda. However, other critical factors are given that are external to these actions and on which their overall success is dependent. In reviewing these factors as a group we conclude that far greater understanding of the partnership formation process and its dynamic in engendering successful sustainable development decision-making processes is crucial to move beyond the rhetoric of partnerships and enter the more complex and difficult world of truly participatory approaches.     

Identification of a novel PCB source through analysis of 209 PCB congeners by US EPA modified method 1668

PCDD/Fs and PCBs in surface waters and effluent waste streams flowing into New York/New Jersey Harbor were sampled by large volume filtration and solid phase extraction (XAD-2). Passive hexane samplers were employed in sewer trackdown. Extraction media were analyzed for 2,3,7,8 substituted PCDD/Fs and all 209 PCB congeners. The non-Aroclor PCB congener, 3,3^′-DiCB, was ubiquitous in the harbor and was found to be associated with pigment manufacture. Knowledge of inadvertent synthesis of non-Aroclor PCBs is not new but its magnitude and the generation of congeners with dioxin-like properties from this process is novel.     

Use and misuse of motor-vehicle crash death rates in assessing highway-safety performance

OBJECTIVES: The objectives of the article are to assess the extent to which comparisons of motor-vehicle crash death rates can be used to determine the effectiveness of highway-safety policies over time in a country or to compare policy effectiveness across countries. METHODS: Motor-vehicle crash death rates per mile traveled in the 50 U.S. states from 1980 to 2003 are used to show the influence on these rates of factors independent of highway-safety interventions. Multiple regression models relating state death rates to various measures related to urbanization and demographics are used. RESULTS: The analyses demonstrate strong relationships between state death rates and urbanization and demographics. Almost 60% of the variability among the state death rates can be explained by the independent variables in the multiple regression models. When the death rates for passenger vehicle occupants (i.e., excluding motorcycle, pedestrian, and other deaths) are used in the regression models, almost 70% of the variability in the rates can be explained by urbanization and demographics. CONCLUSIONS: The analyses presented in the article demonstrate that motor-vehicle crash death rates are strongly influenced by factors unrelated to highway-safety countermeasures. Overall death rates should not be used as a basis for judging the effectiveness (or ineffectiveness) of specific highway-safety countermeasures or to assess overall highway-safety policies, especially across jurisdictions. There can be no substitute for the use of carefully designed scientific evaluations of highway-safety interventions that use outcome measures directly related to the intervention; e.g., motorcyclist deaths should be used to assess the effectiveness of motorcycle helmet laws. While this may seem obvious, there are numerous examples in the literature of death rates from all crashes being used to assess the effectiveness of interventions aimed at specific subsets of crashes.     

Prey growth and size-dependent predation in juvenile estuarine fishes: experimental and model analyses

The outcome of predation interactions between growing, size-structured predator and prey cohorts is difficult to predict. We manipulated the food resources available to juvenile spot subject to predation from southern flounder in a 60-day replicated pond experiment to test the hypothesis that spot growing slowly would experience higher predation mortality and stronger selection against small individuals than those growing rapidly. A nearly threefold difference in average growth rate between fast- and slow-growth treatments led to twofold higher predation mortality of slow-growing spot. Relative to no-flounder controls, larger spot were overrepresented at the end of the experiment in both treatments, but the magnitude of flounder size selection was much greater in the slow-growth treatment. The experimental results agreed qualitatively, but not quantitatively, with predictions from a prior size-dependent foraging model. In particular, the model significantly underestimated observed shifts in spot size structure to larger sizes. We hypothesized that competitive release and associated increases in spot growth due to thinning by flounder might reconcile this difference, and extended the model to incorporate this process. We then used the model to estimate the relative contribution of these two confounded predator effects (size-selective predation and thinning) to observed shifts in spot size structure. Model simulations indicated that the combined effects of size-selective predation and thinning could account for nearly all of the observed shift in spot size structure, but that thinning was the more important process. Our results highlight the utility of combining experimental and modeling approaches to unravel the complexities underlying interactions between growing, size-structured predator and prey cohorts.     

Empirical evaluation of neutral theory

We describe a general framework for testing neutral theory. We summarize similarities and differences between ten different versions of neutral theory. Two central predictions of neutral theory are that species abundance distributions will follow a zero-sum multinomial distribution and that community composition will change over space due to dispersal limitation. We review all published empirical tests of neutral theory. With the exception of one type of test, all tests fail to support neutral theory. We identify and perform several new tests. Specifically, we develop a set of best practices for testing the fit of the zero-sum multinomial (ZSM) vs. a lognormal null hypothesis and apply this to a data set, concluding that the lognormal outperforms neutral theory on robust tests. We explore whether a priori parameterization of neutral theory is possible, and we conclude that it is not. We show that non-curve-fitting predictions readily derived from neutral theory are easily falsifiable. In toto, there is a current overwhelming weight of evidence against neutral theory. We suggest some next steps for neutral theory.