Evaluation of scheduling strategies for a dynamic job shop in a tool-shared,flexible manufacturing environment

A two-phase approach is used to examine the impact of job scheduling rules and tool selection policies for a dynamic job shop system in a tool-shared, flexible manufacturing environment. The first phase develops a generalized simulation model and analyses 'simple' job scheduling rules and tool selection policies under various operating scenarios. The results from this investigation are then used to develop and analyse various bi-criteria rules in the second phase of this study. The results show that the scheduling rules have the most significant impact on system performance, particularly at high shop load levels. Tool selection policies affect some of the performance measures, most notably, proportion of tardy jobs, to a lesser degree. Higher machine utilizations can be obtained at higher tool duplication levels but at the expense of increased tooling costs and lower tool utilization. The results also show that using different processing time distributions may have a significant impact on shop performance.     

Relations between stressors and group perceptions: Main and mediating effects

Most orgnizations these days utilize groups for the performance of at least some tasks. There is therefore a need to examine the relationthip between job stressors and group functioning. Until now it has been proposed that employees who perceive high levels of stress in their jobs will have negative perceptions of the groups in which they work, in the form of reduced altruism and collective efficacy. They may also have higher levels of psychological strain. This study examined relations between job-related stressors and group perceptions (collective efficacy 3rd the prevalence of altruistic behaviour) in a sample of 2403 mililitary personnel, comprising 31 companies in two US Anny combat brigades. We also examined whether group perceptions mediated the relationship between stressors and both job satisfaction and subjective well-being. Results indicated that stressors were negatively associated with measures of group perceptions, and both job satisfiction and well-being. Furthermore, mediated regression analyses suggested that relations between interpersonal conflict and both job satitfaction and well-being were partially mediated by both group perception measures. These finding suggest that work-related stressors may negatively impact on group functioning, which may lead to employee strains. Implications of these finding are discussed, and suggestions are made for future research.     

Effects of resident-oriented care on job characteristics of nursing caregivers

This study evaluates the effects of the implementation of resident-oriented care on the job characteristics (job autonomy, job demands and social support) of nursing caregivers in three Dutch nursing homes. In a quasi-experimental design, experimental and control groups in both general and psychogeriatric wards were followed for up to 22 months, using a pre-test and two post-tests by means of written questionnaires and semi-structured interviews. The results showed that the intervention appeared to be partly successful. Last post-test regression analyses revealed significant increases in a number of design characteristics of resident-oriented care. Significant increases were noticed on resident assignment, the two variables measuring the nursing process and, in the psychogeriatric experimental group, on resident-oriented tasks (p≤.01). The effects on job characteristics were limited. An indicative increase was shown in contextual job autonomy in the experimental group (p≤.05). The qualitative data derived from the interviews showed that there was still a partly task-oriented division of labour. Further, the delegation of co-ordination tasks to nursing caregivers had not yet been properly achieved. The study concludes with some theoretical and methodological reflections in the light of the findings.     

Job tenure as a moderator of stressor–strain relations: A comparison of experienced and new-start teachers

Abstract

Few studies have investigated the extent to which the effects of work stressors on strain change over the duration of employees’ job incumbencies. Drawing on Karasek's (1979) job demands-control-support model, the current study examined the moderating influence of job tenure (experienced versus novice worker status) on stressor-strain relations. Using a sample of 422 experienced and 248 beginning schoolteachers in Australia, job factors and job strain were assessed on two occasions, 8 months apart. Analyses revealed that the three job factors were each correlated with strain as predicted, although the (elusive) demands×control interaction effect was evidenced amongst “new-start” teachers only. The findings provide mixed support for Karasek's model, and draw attention to the need to consider the role of job tenure and career stage in studies of work stress, as work stressor-strain effects may be routinely underestimated in research that ignores these factors.     

Relationships between stressful work environments and bullying: Results of a large representative study

Abstract

This paper contributes to the relatively sparse knowledge about relationships between stressful work environments and bullying. Relationships between job stressors and leadership behaviour were analysed as possible predictors of bullying at work on the basis of the work environment hypothesis, which states that stressful and poorly organized work environments may give rise to conditions resulting in bullying. Analyses of a representative sample (n=2539) of the Norwegian workforce showed role conflict, interpersonal conflicts, and tyrannical and laissez-faire leadership behaviour to be strongly related to bullying, and that the strength of associations to a high degree differed for various measures of bullying. Support was found for an interactive relationship between decision authority and role conflict at different levels of laissez-faire leadership. Not only targets and bully/targets but also bystanders assessed their work environment more negatively than did non-involved employees, while perpetrators of bullying did not differ significantly from non-involved employees as regards their perception of the work environment. Hence, bullying is likely to prevail in stressful working environments characterized by high levels of interpersonal friction and destructive leadership styles. In addition, bullying is particularly prevalent in situations where the immediate supervisor avoids intervening in and managing such stressful situations.     

Job resources and emotional exhaustion: The mediating role of learning opportunities

The Job Demands-Resources model predicts that job demands increase and job resources decrease emotional exhaustion in employees. In this study, we investigated one possible mechanism for this, in order to provide a deeper insight into the role of job resources in this energy-depletion process. We assumed that job resources (autonomy and task variety) reduce emotional exhaustion through the promotion of opportunities for personal growth and development, especially workplace learning. Moreover, we expected that job demands (workload, cognitive and emotional demands) would be positively related to work-related learning opportunities. Our research model was tested in a large and heterogeneous sample out of the Dutch working population (N = 4589), following a cross-validation procedure. Multi-group structural equation modelling revealed that autonomy and task variety promoted learning opportunities, which in turn partially mediated between these job resources and emotional exhaustion. With respect to job demands, our study showed mixed results: cognitive demands promoted learning opportunities, workload frustrated such opportunities, and emotional demands were not significantly related to learning opportunities. Our results contribute to a better understanding of the interplay between job demands, job resources and learning opportunities in the energy-depletion process, and support the need for the promotion of learning opportunities in the workplace.     

Decision latitude,job demands,and employee well-being

Abstract

Karasek (1979) drew attention to the possibilities that job characteristics may be non-linearly associated with employee well-being, and that they may combine interactively in relation to well-being. This paper examines those issues, and finds that both linear and non-linear components are present in relationships between job features and well-being. However, there is no evidence for a synergistic interaction between decision latitude and job demands. Those job features are differentially predictive of two aspects of well-being: job-related depression-enthusiasm and anxiety-contentment.     

The recruitment and selection of hospital medical consultants

Abstract

The literature on selection has been dominated in recent decades by the ‘prediction’ paradigm. Such an approach requires a substantial number of positions to be filled in order to compute validity coefficients. There are other approaches, using a different paradigm, when concentrated on adjusting the organization and the employee. Here careful analysis of job demands is essential. This article describes such an analysis, taking the medical consultant as an example. The method can be used in an iterative way. It is useful when one has to work with small numbers of positions.     

Lifestyle habits,substance use and predictors of job burnout in professional working women

Abstract

This study explores differences in self-reported lifestyle habits, substance use (alcohol, drugs and smoking) and predictors of job burnout in a sample of 879 professional working women employed in dental health ofices in a cross-sectional design. Job burnout was measured using the Maslach Burnout Inventory (MBI) and self-reported substance use and lifestyle habits were assessed using the Stress Assessment Profile. Self-reported drinking, smolung and drug use were only modestly correlated with each other in this sample. Employed women with higher levels of drinking reported significantly lower quality overall lifestyle practices, eating/nunition habits, and more frequent use of avoidant coping strategies in the face of work and life hassles compared to non-drinkers. Women who smoked also reported significantly lower overall lifestyle practices and eating/nutrition habits. Those who reported using drugs for recreational purposes reported significantly greater hassles, poorer lifestyle habits, a less hardy outlook on life, and more frequent use of dysfunctional coping strategies. Although women who reported using drugs experienced significantly higher interpersonal burnout (depersonalization) compared to non-drug users, in general, self-reported substance use was not significantly related to job burnout. After controlling for age and psychological distress, perceived stress, type A behaviour, cognitive hardiness and lifestyle habits significantly contributed to predictions of job burnout in multiple regression analyses. Despite methodological limitations, the prevalence of substance use found in this study supports previous research findings. Professional working women who practise poor lifestyle and health habits appear to be at risk of experiencing job burnout.     

The effect of objective job demands on registered sickness absence spells; do personal,social and job-related resources act as moderators?

Abstract

This study applied Karaseks demand-control model, using sense of coherence (SOC), social support and job control as moderators of effects of job demands on ensuing sickness absence spells in a 3-year follow-up of 856 municipal employees. Among men the results supported the active learning hypothesis. Passive jobs predicted a high number of sickness absence spells and active jobs predicted a low number of spells. for short spells (1-3 days), the demand-control interaction, however, depended on SOC. In active jobs SOC was negatively associated with sickness absence spells; in passive jobs no such association was found. For long spells (3 days), the demand-control interaction depended on occupational level; active jobs were predictive of low absence spells among blue collar men. Among women, the results supported the strain hypothesis. The demand-control interaction, however, depended on household size. In small households, high-strain jobs predicted a high number of spells, while no increase in spells was found in active versus low-strain jobs. In larger households, the number of spells correlated positively with increasing demands even when control was good. The demand-control interaction, however, depended on SOC and spouse support. With strong SOC or spouse support, absence spells in active jobs remained on a relatively low level, otherwise active jobs led to a high number of spells. This suggests that SOC and spouse support may act as protective factors against female role conflicts associated with active jobs