The objective of this study is to develop a quantified method for determining the mental workload imposed on train control officers (TCOs) and to express this mental workload by means of an index that is objective and can stand up to the tests of validity and reliability. The method addresses an existing operational shortcoming in Spoornet train control operations and could be used as a tool for predicting the mental workload imposed on operators at particular train control centres. The method could be applied to manage and improve operational safety in the rail transport environment. A participative systems approach was followed in the development of the measuring methodology. A work group comprising expert users of the specific train control system was involved in identifying task factors and assigning weights for task and moderating factors. The newly developed Mental Workload Index (MWLI) consists of three task factors and eleven moderating factors, each with a different weight in terms of its contribution to overall mental workload. The work group performed several iterations to reach final consensus on the following task factors and their respective contributions to the MWLI: the number of data transactions, the number of authorisations, and the number of communications via telephone and radio. The systems approach used in the development process is discussed, and the final index with the task and moderating factors is presented. In conclusion, the value and possible application of the MWLI are discussed. The MWLI is shown to provide an objective method for the assessment and prediction of mental workload in the train control environment. / Thesis (PhD)--University of Pretoria, 2008. / Electrical, Electronic and Computer Engineering / unrestricted

Workload transitions are situations where operators are suddenly confronted with levels of workload substantially different from previously established levels. Workload transitions may affect the operators' state of stress and coping behaviors but previous research has not conclusively demonstrated the nature of those. The first goal of the current work was to investigate the discrepant findings of the previous literature. Two experiments were conducted where participants were asked to perform a digit detection task that suddenly shifted between low and high event rates (i.e., low and high workload, respectively). The first experiment used a large magnitude transition that resulted in a decrease in reported levels of task engagement and effort. Over time, the reported stress and workload ratings of the transitioned groups approached the nontransitioned control groups. A second experiment was conducted using a moderate magnitude transition. This second experiment replicated the findings from the first experiment, with the key difference being that the transition from a low to more a more moderate level of workload resulted in higher, sustained task engagement and effort. Two main conclusions are drawn from these results. First, over time the stress and workload levels of individuals who experience a transition will approach those reported by nontransitioned individuals. Future workload transition research must therefore consider the effect of the time from transition. Second, the magnitude of the transition may influence the coping response such that a moderate transition may result in increased task-oriented, effortful coping whereas a large magnitude transition may result in decreased effortful coping.

Current literature reflects escalating concerns regarding the potential organisational damage that can result from overloaded and under loaded workforces. Overloaded and under loaded workforces have been linked to poor employee well-being, reduced productivity, dissatisfaction and higher turnover rates. This study aimed to develop a scale for the measurement of workload within South African organisations. The initial scale contained six dimensions and a total of 71 items. These items were then sent to subject matter experts in order to determine their content validity. The survey was then completed by 224 employed individuals. An exploratory factor analysis (EFA) was performed and six factors were indicated. The overall reliability of the scale was highly satisfactory with inter-correlations between scale items. The results suggest that the South African Workload Scale (SAWS) is a promising instrument for the measurement of workload within South African organisations. Copyright 2010, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Myburgh, T 2010, A workload inventory for South African Organisations, MCom dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-02212012-115206 / > C12/4/64/gm / Dissertation (MCom)--University of Pretoria, 2010. / Human Resource Management / unrestricted

This dissertation presents two studies examining the interaction between workload history and driver mental workload. The first experiment focuses on testing for the presence of a hysteresis effect in the driving task. The second experiment examines the proposition that cueing impending periods of higher task demand can reduce the impact of any such potential hysteresis effects. Thirty-two licensed drivers served as participants and all served in both studies. Using the directions provided by a Heads-Up-Display navigation system, participants followed a pre-set route in the simulated environment. At specified points within the drive, the navigation system would purposefully fail which required drivers to relay a ten digit alphanumeric error code to a remote operator in order to reset the system. Results indicated that this increase in task demand from the navigation system's failure leads to a significant increase in perceived mental workload as compared to pre-failure periods. This increase in driver mental workload was not significantly reduced by the time the drive ended, indicating the presence of a hysteresis effect. In the second experiment, the navigation system provided a completely reliable visual warning before failure. Results indicate that cueing had neither an effect on perceived mental workload, nor any ameliorating effect on the hysteretic type effect seen in mental workload recovery. The conclusion of these findings being that the overall safety and efficiency of the surface transportation system would likely improve by designs which accommodate the periods immediately following a reduction in stress. Whether from leaving high demand areas such as work zones or in the period immediately after using a in-car information device such as a GPS or a cell phone, these post-high workload periods are associated with increased variability in driver inputs and levels of mental workload.

Managing workload allocation to ensure fairness and equity amongst staff can be a challenge in any organisation and managing the workload allocation of autonomy seeking academic staff in a business school can be even more so. In this study, the researcher aimed to review a recently designed and implemented academic workload allocation model in a South African business school in order to establish whether the model and implementation system has been successful in contributing to actual and perceived fairness and equity in workload distribution amongst their academic staff. The researcher did this by using a sequential exploratory mixed methods approach, first reviewing documentary evidence, which informed the design of an online survey with the academic staff, followed by semi-structured interviews with a sample group. The study reveals that the model, and the way it was implemented and managed, failed to achieve its intended aims of increased equitable and fair workloads amongst academic staff. These implementation failures have resulted in negative consequences for the organisational culture. Staff satisfaction and engagement with the model, its implementation and management does not present positively in the findings of this study. In the South African context where there are very few studies related to academic workload allocation models, the results of this study may be valuable for higher education institutions considering the introduction or review of workload models amongst their academic staff. The study highlights the importance of an inclusive and careful design approach, change management considerations during the implementation phase, and the transparent management of the workload allocation process and results.

Workload is defined as the cost incurred by an individual, given their capacities, while achieving a particular level of performance on a task with specific demands. Demands of a task or combination of tasks may include maintaining postural stability, executing physical actions, and/or performing cognitive tasks. While there have been attempts to establish a physiological measure of concurrent physical and mental workload, as yet there has been no work towards developing a single subjective method of evaluation. Select subjective assessment methodologies were evaluated quantitatively during laboratory-based experiments. Concurrent execution of mental and physical activity was required at various levels, since it was desired to be able to measure mental workload, physical workload, and also evaluate their interaction. Measurements of task performance were investigated to evaluate the effects of combined mental and physical demands and establish which subjective assessments were accurate and sensitive to changes in workload. The utility of existing subjective assessment tools created for one domain appeared to be limited when evaluating multi-task situations requiring substantial mental and physical activity. Further clarification of the impact of different types of physical demand on cognitive processing, performance and subjective workload assessment of a constant mental task was addressed in the second experiment. This experiment investigated the effect of several activity types, specifically global versus localized effort, changes in load, and different task frequencies. The results provided support that the type of activity, load and frequency of task influence subjective mental workload assessment scores and performance. Not all existing assessment tools accurately represented an individual's ability to perform a task when there was a combination of physical and mental demands. A unidimensional tool is suggested as a screening tool to identify situations requiring excessive or increased mental workload. Alternative methods, possibly a new multidimensional tool, should be developed to obtain more detailed information so ratings of workload for different tasks may be compared. Effectiveness of a subjective stability assessment tool was evaluated in situations demanding mental activity while maintaining an upright posture. Tests were performed over a wide range of conditions, including various mental loads, sensory conditions, and postural stances. The purpose was to determine the effects of each task variation on the perception of postural stability. Postural sway increased with task difficulty, regardless of the source (i.e. postural stance, visual condition, mental workload). The addition of mental workload did not alter the non-linear relationship between objective measures of postural sway and perceptions of postural stability. Since decrements in balance are well perceived, subjective assessment tools may be incorporated in control strategies to minimize falls. / Ph. D.

The purpose of this study is focus on the relationship among the sense of calling, workload and work satisfaction. Using police officers as the research subject, this study also intends to discuss the concept and the importance of the sense of calling. The results of this study show that older and married male, with longer tenure and higher ranking, seem to display higher degree of the sense of calling. Furthermore, the results also indicate that the sense of calling is positively related to work satisfaction, and surprisingly, is positively related to workload as well, which may imply the opposite sides of the influences of the sense of calling. Considering the strong link among the sense of calling, workload, and work satisfaction, it is believed that the sense of calling might play a critical role in the working context. Also, the concept of the sense of calling may differ from the previous illustration under the Chinese culture and in the specific occupational context, i.e. police; therefore, it should be worth to discuss in the future studies.

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published_or_final_version / Electrical and Electronic Engineering / Master / Master of Philosophy

Workload adaptation is a performance management process in which an autonomic database management system (DBMS) efficiently makes use of its resources by filtering or controlling the workload presented to it in order to meet its Service Level Objectives (SLOs). It is a challenge to adapt multiple workloads with complex resource requirements towards their performance goals while taking their business importance into account. This thesis studies approaches and techniques for workload adaptation. First we build a general framework for workload adaptation in autonomic DBMSs, which is composed of two processes, namely workload detection and workload control. The processes are in turn made up of four functional components - workload characterization, performance modeling, workload control, and system monitoring. We then implement a query scheduler that performs workload adaptation in a DBMS, as the test bed to prove the effectiveness of the framework. The query scheduler manages multiple classes of queries to meet their performance goals by allocating DBMS resources through admission control in the presence of workload fluctuation. The resource allocation plan is derived by maximizing the objective function that encapsulates the performance goals of all classes and their importance to the business. First-principle performance models are used to predict the performance under the new resource allocation plan. Experiments with IBM® DB2® are conducted to show the effectiveness of the framework. The effectiveness of the workload adaptation depends on the accuracy of the performance prediction. Finally we introduce a tracking filter (Kalman filter) to improve the accuracy of the performance prediction. Experimental results show that the approach is able to reduce the number of unpredicted SLO violations and prediction errors. / Thesis (Ph.D, Computing) -- Queen's University, 2008-01-28 21:22:25.139