Single-machine batch delivery scheduling with an assignable common due window

This paper addresses a batch delivery single-machine scheduling problem in which jobs have an assignable common due window. Each job will incur an early (tardy) penalty if it is early (tardy) with respect to the common due window under a given schedule. There is no capacity limit on each delivery batch, and the cost per batch delivery is fixed and independent of the number of jobs in the batch. The objective is to find the optimal size and location of the window, the optimal dispatch date for each job, as well as an optimal job sequence to minimize a cost function based on earliness, tardiness, holding time, window location, window size, and batch delivery. We show that the problem can be optimally solved in O(n⁸)$O(n^8)$ time by a dynamic programming algorithm under a reasonable assumption on the relationships among the cost parameters. A computational experiment is also conducted to evaluate the performance of the proposed algorithm. We also show that some special cases of the problem can be optimally solved by lower order algorithms.     

Hierarchical model to design manufacturing systems applied to a metal-mechanic company

This paper describes the application of a model to design and manage the manufacturing process through an integrated system, using a Hierarchical methodology-by means of different aggregation and disaggregation stages with an appropriate time horizon. The hierarchical model obtained allows interfacing between the master schedule and the schedule of the orders. At each level of the hierarchical model some decisions have to be made in order to design the manufacturing system, but having a model that also takes into consideration the management of the system. To do this it is necessary to use aggregated information concerned with the level at which decisions are made. It is obtained from the database, which contains the information at the highest level of aggregation. This model has been applied to a metal mechanic company, that makes final products such as car washers, etc. The benefits of this approach for the company are addressed in this paper.     

Measuring Sharedness of Team-Related Knowledge: Design and Validation of a Shared Mental Model Instrument

Many researchers have explored how people share and construct similar mental models in teams. They have claimed that successful team performance depends on a shared mental model of team members about task, team, equipment and situation. Most of the literature has illustrated simplified relationships between a team's mental model and their performance without a valid instrument addressing the confined and relevant constructs of a shared mental model. This paper describes the instrument development steps and the conceptual framework for factors associated with shared mental models. After development and refinement, the instrument was finalized for use to measure team-related knowledge. The final instrument consists of 42 items that are linked to the five emergent factors of shared mental models including general task and team knowledge, general task and communication skills, attitude toward teammates and task, team dynamics and interactions, and team resources and working environment.     

Managers' personal values as predictors of importance attached to training and development: a cross-country exploratory study

Few empirical studies have examined the effect of personal values on the importance attached by individuals to training and development in organizations. We argue that personal values play an important role in decision-making processes (i.e. commitment to training and development) and that such values are the product of socialization processes operating at an organizational and societal level. Questionnaire data were collected from 340 Irish and Canadian line managers to test the hypothesis that personal values affect the importance attached by respondents to training and development. Capability values were found to be a significant positive predictor of the perceived importance of training and development. The findings emphasize the need for simultaneously examining both personal values and organizational factors as predictors of training and development activity.     

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.     

Investigating effort–reward imbalance and work–family conflict in relation to morningness–eveningness and shift work

Abstract

An increasingly older workforce and a growing emphasis on jobs involving interaction with computers have resulted in a need to more carefully examine the relationship between ageing and computer-based work. In this study, a sample of 394 subjects ranging in age from 20-75 years performed a computer task across a 3-day period. Three different types of computer-based jobs (data entry, information retrieval, and accounts balancing) performed at three large US companies were simulated. Age differences in the subjective experience of stress, workload, and bodily discomfort were evaluated. The results indicated that age effects for these measures varied according to task. The older subjects perceived greater workload for the more mentally challenging problem-solving oriented accounts balancing task (Which involved a graphical user interface) than the younger participants, even with increased exposure to the task. However, the older subjects generally experienced less stress than the younger subjects on an information retrieval task that involved a more socially interactive telephone component. A positive relationship between the frustration component of workload and the measure of stress was also found, suggesting an important link between the constructs of stress and workload. Overall, the outcomes of this study provide important insights into design interventions intended to accommodate older as well as younger persons in the workforce.     

Bored employees misbehaving: The relationship between boredom and counterproductive work behaviour

In this study, the relationships among boredom proneness, job boredom, and counterproductive work behaviour (CWB) were examined. Boredom proneness consists of several factors, which include external stimulation and internal stimulation. Given the strong relationships between both the external stimulation factor of boredom proneness (BP-ext) and anger as well as the strong relationship between trait anger and CWB, we hypothesized that examining BP-ext would help us to better understand why employees commit CWB. Five types of CWB have previously been described: abuse against others, production deviance, sabotage, withdrawal and theft. To those we added a sixth, horseplay. Using responses received from 211 participants who were recruited by email from throughout North America (112 of them matched with co-workers), we found support for our central premise. Indeed, both BP-ext and job boredom showed significant relationships with various types of CWB. The boredom proneness factor also moderated the relationship between job boredom and some types of CWB, suggesting that a better understanding of boredom is imperative for designing interventions to prevent CWB.     

Personality factors predicting changes in shift work tolerance: A longitudinal study among nurses working rotating shifts

Abstract

The aim of the present study was to investigate the relationship between personality factors (hardiness, morningness, flexibility, and languidity) and longitudinal changes on different measures of shift work tolerance (fatigue, sleepiness, anxiety and depression) over one year among nurses working rotating shifts. A total of 642 female Norwegian nurses working in a rotating three-shift schedule participated in the study. The cohort was established by age-stratified selection among members of the Norwegian Nurses Association in 2008. Questionnaires were administered in 2008/2009 (T1) and in 2009/2010 (T2). The results showed that hardiness was negatively related to fatigue, anxiety and depression at T2 when controlling for the scores on these constructs at T1. Morningness was not related to any indicators of shift work tolerance at T2 when controlling for shift work tolerance at T1. Flexibility was negatively related to anxiety at T2 when controlling for anxiety at T1. Languidity was positively related to sleepiness and fatigue at T2 when controlling for sleepiness and fatigue at T1. The findings indicate that personality factors, especially hardiness, can predict changes related to shift work tolerance over a period of one year.     

An expanded typology of conflict at work: Task,relationship and non-task organizational conflict as social stressors

This study investigated the roles of three types of conflict at work – task, relationship and non-task organizational – in predicting employee strain. These conflict types refer to disputes over issues that are, respectively, work-task specific, driven by emotionally charged interpersonal animosity or rooted in more broad organizationally relevant issues. Findings from a sample of 260 working adults from various organizations in the United States supported the notion that the three types of conflict function as social stressors and are related to a variety of psychological, behavioural and physical strains. They extend previous research based primarily on relationship conflict. Non-task organizational conflict emerged as a key predictor across strain criteria, thus highlighting the importance of including a more complete conceptualization of the conflict construct in social stress research. The results for task conflict are at variance with findings that it can be beneficial, and suggest that its negative relationship with well-being may be due to its co-occurrence with the other forms of conflict. These findings provide support for an expanded typology of conflict.     

Illegitimate tasks are not created equal: Examining the effects of attributions on unreasonable and unnecessary tasks

ABSTRACT

Illegitimate tasks are tasks that violate norms for what the employee should do as part of the job, and have been found to harm employees’ well-being. The current research uses a mixed methods design to examine the role of attributions on the two types of illegitimate tasks: unreasonable and unnecessary tasks. A sample of 432 engineers described a specific illegitimate task that was assigned to them, the attributions they made and their response. They also completed a quantitative questionnaire. Results from both the qualitative (event level) and quantitative (person level) portions of our study portray differences in the attributions made to unreasonable and unnecessary tasks, as well as differential negative effects on employees’ emotions. In addition, hostile attribution bias was found to moderate the relationship between illegitimate tasks and negative emotions, particularly for unreasonable tasks. This supports the theoretical basis for illegitimate tasks because unreasonable tasks pose a potentially greater risk to the employee’s self-worth than unnecessary tasks that are more often assigned at random.