Beneficial effects on employment and preventive health care: the concept and results of counselling processes from a German project

Since December 1998 a project of working time counselling named "Design of Modern Working Times" is supported by the federal state of North Rhine-Westphalia in Germany and the European Union; AWiS-consult is entrusted to carry out this project. The service offered to all companies, institutions, work committees, and employees interested covers information, assessment of existing working time schedules, development of alternative or new working time schedules, and accompanying implementation processes. Up to June 2001 nearly 300 inquiries were worked on, most of them from industry, service companies, and from the field of care and hospitals. Working time design in this project aims not only at work safety and health care but also at beneficial effects on employment. In a special campaign from May 2000 to May 2001, 61 companies were supported by AWiS-consult, with the result of more than 400 new employees and 16 companies with employment secured, so the combination of preventive health care and beneficial effects on employment by working time design can be assessed as successful.     

Compensation for Unfavorable Characteristics of Irregular Individual Shift Rotas

Some employees of TV companies, such as those who produce remote TV programs, have to cope with very irregular rotas and many short‐term schedule deviations. Many of these employees complain about the negative effects of such on their wellbeing and private life. Therefore, a working group of employers, council representatives, and researchers developed a so‐called bonus system. Based on the criteria of the BESIAK system, the following list of criteria for the ergonomic assessment of irregular shift systems was developed: proportion of night hours worked between 22∶00 and 01∶00 h and between 06∶00 and 07∶00 h, proportion of night hours worked between 01∶00 and 06∶00 h, number of successive night shifts, number of successive working days, number of shifts longer than 9 h, proportion of phase advances, off hours on weekends, work hours between 17∶00 and 23∶00 h from Monday to Friday, number of working days with leisure time at remote places, and sudden deviations from the planned shift rota. Each individual rota was evaluated in retrospect. If pre‐defined thresholds of criteria were surpassed, bonus points were added to the worker's account. In general, more bonus points add up to more free time. Only in particular cases was monetary compensation possible for some criteria. The bonus point system, which was implemented in the year 2002 for about 850 employees of the TV company, has the advantages of more transparency concerning the unfavorable characteristics of working‐time arrangements, incentive for superiors to design “good” rosters that avoid the bonus point thresholds (to reduce costs), positive short‐term effects on the employee social life, and expected positive long‐term effects on the employee health. In general, the most promising approach to cope with the problems of shift workers in irregular and flexible shift systems seems to be to increase their influence on the arrangement of working times. If this is not possible, bonus point systems may help to achieve greater transparency and fairness in the distribution of unfavorable working‐time arrangements within a team, and even reduce the unnecessary unfavorable aspects of shift systems.     

Flexible working hours and well-being in Finland

Flexibility of working hours became more prevalent in the 1990s in Finland. According to a representative survey on Finnish wage and salary earners (n = 1790) at the beginning of 2000, a great majority of male (76%) and female (65%) employees regularly worked overtime and/or had irregular working hours every month. These employees were flexible in meeting the needs of their companies/employers. Individual flexibility of working hours was far less common, only one third of male and female employees were able to regulate their working hours. A better balance between company-controlled and individual flexibility would, however, improve the well-being of employees. Employees working overtime without being allowed to regulate their working hours felt more symptoms of distress and had more conflicts in combining workplace and family roles than those who could individually determine their working hours flexibly. An investment in individually determined flexibility, for example by means of participatory planning, would improve the well-being of employees, and thus also improve the productivity of the organization.     

Compensation for unfavorable characteristics of irregular individual shift rotas

Some employees of TV companies, such as those who produce remote TV programs, have to cope with very irregular rotas and many short-term schedule deviations. Many of these employees complain about the negative effects of such on their wellbeing and private life. Therefore, a working group of employers, council representatives, and researchers developed a so-called bonus system. Based on the criteria of the BESIAK system, the following list of criteria for the ergonomic assessment of irregular shift systems was developed: proportion of night hours worked between 22:00 and 01:00 h and between 06:00 and 07:00 h, proportion of night hours worked between 01:00 and 06:00 h, number of successive night shifts, number of successive working days, number of shifts longer than 9 h, proportion of phase advances, off hours on weekends, work hours between 17:00 and 23:00 h from Monday to Friday, number of working days with leisure time at remote places, and sudden deviations from the planned shift rota. Each individual rota was evaluated in retrospect. If pre-defined thresholds of criteria were surpassed, bonus points were added to the worker's account. In general, more bonus points add up to more free time. Only in particular cases was monetary compensation possible for some criteria. The bonus point system, which was implemented in the year 2002 for about 850 employees of the TV company, has the advantages of more transparency concerning the unfavorable characteristics of working-time arrangements, incentive for superiors to design “good” rosters that avoid the bonus point thresholds (to reduce costs), positive short-term effects on the employee social life, and expected positive long-term effects on the employee health. In general, the most promising approach to cope with the problems of shift workers in irregular and flexible shift systems seems to be to increase their influence on the arrangement of working times. If this is not possible, bonus point systems may help to achieve greater transparency and fairness in the distribution of unfavorable working-time arrangements within a team, and even reduce the unnecessary unfavorable aspects of shift systems.     

Flexible Working Hours,Health, and Well-Being in Europe: Some Considerations from a SALTSA Project

The project brought together researchers from 9 EU-Countries and resulted in a number of actions, in particular the following: (a) There is an urgent need of defining the concept of flexible working hours, since it has been used in many different and even counterintuitive ways; the most obvious distinction is where the influence over the working hours lies, that is between the “company-based flexibility” and the “individual-oriented flexibility”; (b) The review of the Legislation in force in the 15 European countries shows that the regulation of working times is quite extensive and covers (Council Directive 93/104/EC) almost all the various arrangements of working hours (i.e., part-time, overtime, shift, and night work), but fails to provide for flexibility; (c) According to the data of the Third EU Survey on Working Conditions, longer and “irregular” working hours are in general linked to lower levels of health and well-being; moreover, low (individual) flexibility and high variability of working hours (i.e., company-based flexibility) were consistently associated with poor health and well-being, while low variability combined with high autonomy showed positive effects; (d) Six substudies from different countries demonstrated that flexible working hours vary according to country, economic sector, social status, and gender; overtime is the most frequent form of company-based flexibility but has negative effects on stress, sleep, and social and mental health; individual flexibility alleviates the negative effects of the company-based flexibility on subjective health, safety, and social well-being; (e) The literature review was able to list more than 1,000 references, but it was striking that most of these documents were mainly argumentative with very little empirical data. Thus, one may conclude that there is a large-scale intervention ongoing in our society with almost completely unknown and uncontrolled effects. Consequently, there is a strong need for systematic research and well-controlled actions in order to examine in detail what flexible working hours are considered, what and where are their positive effects, in particular, as concerns autonomy, and what regulation seem most reasonable.     

Process flexibility: design, evaluation, and applications

One of the most effective ways of minimizing supply/demand mismatch costs, with little increase in operational costs, is to deploy valuable resources in a flexible and timely manner to meet the realized demand. This notion of flexible processes has significantly changed operations in many manufacturing and service companies. For example, a flexible production system is now commonly used by automobile manufacturers, and a workforce cross-training system is now a common practice in many service industries. However, there is a trade-off between the level of flexibility available in the system and the associated complexity and operating costs. The challenge is to have the “right” level of flexibility to capture the bulk of the benefits from a fully flexible system, while controlling the increase in implementation costs. This paper reviews developments in process flexibility over the past decade. In particular, we focus on the phenomenon, often observed in practice, that a slight increase in process flexibility can lead to a significant improvement in system performance. This review explores the issues from three perspectives: design, evaluation, and applications. We also discuss how the concept of process flexibility has been deployed in several manufacturing and service systems.     

A New Approach for Evaluating Flexible Working Hours

Recent studies on flexible working hours show at least some of these working time arrangements seem to be associated with impairing effects of health and well-being. According to available evidence, variability of working hours seems to play an important role. The question, however, is how this variability can be assessed and used to explain or predict impairments. Based on earlier methods used to assess shift-work effects, a time series analysis approach was applied to the matter of flexible working hours. Data on the working hours of 4 week's length of 137 respondents derived from a survey on flexible work hours involving 15 companies of different production and service sectors in Germany were converted to time series and analyzed by spectral analysis. A cluster analysis of the resulting power spectra yielded 5 clusters of flexible work hours. Analyzing these clusters for differences in reported impairments showed that workers who showed suppression of circadian and weekly rhythms experienced severest impairments, especially in circadian controlled functions like sleep and digestion. The results thus indicate that analyzing the periodicity of flexible working hours seems to be a promising approach for predicting impairments which should be investigated further in the future.     

A new approach for evaluating flexible working hours

Recent studies on flexible working hours show at least some of these working time arrangements seem to be associated with impairing effects of health and well-being. According to available evidence, variability of working hours seems to play an important role. The question, however, is how this variability can be assessed and used to explain or predict impairments. Based on earlier methods used to assess shift-work effects, a time series analysis approach was applied to the matter of flexible working hours. Data on the working hours of 4 week's length of 137 respondents derived from a survey on flexible work hours involving 15 companies of different production and service sectors in Germany were converted to time series and analyzed by spectral analysis. A cluster analysis of the resulting power spectra yielded 5 clusters of flexible work hours. Analyzing these clusters for differences in reported impairments showed that workers who showed suppression of circadian and weekly rhythms experienced severest impairments, especially in circadian controlled functions like sleep and digestion. The results thus indicate that analyzing the periodicity of flexible working hours seems to be a promising approach for predicting impairments which should be investigated further in the future.     

Sexual dimorphism in Odonata: age, size, and sex ratio at emergence

Males and females of many organisms differ in important life-history and behavioral characters. Following a recent optimization analysis of sexually dimorphic life histories, we employed an odonate-like parameter set to identify patterns of life history and behavior to be expected in an odonate population. The default parameter magnitudes generated a smaller body size and shorter development time for males than for females, which resulted in a male-biased sex ratio. Whether population growth was density dependent or density independent, and whether development time was fixed or flexible had major impacts on life-history features. The model generated five general predictions for odonate systems. (1) For species with fixed development times, males and females should differ more in activity level, growth and mortality rates than for species with flexible life cycles. (2) In species with fixed development times, populations at high latitude or high altitude should be more active, emerge and reproduce at smaller size and have a more male-biased sex ratio than low latitude and low altitude populations. (3) In density-dependent populations, with density dependence mediated by activity-dependent mortality, higher predation rates should increase activity levels and reduce development time in species with flexible development times. (4) For species with flexible development times, in strongly density-dependent populations with density dependence mediated by mortality, activity levels should decrease and development times should increase at high prey abundance. (5) Males should be larger at emergence relative to females, and the sex ratio at emergence should be more female-biased in territorial than in non-territorial species. Existing empirical evidence concerning these predictions is generally sparse and equivocal; focused tests are clearly needed.     

Flexible working hours, health, and well-being in Europe: some considerations from a SALTSA project

The project brought together researchers from 9 EU-Countries and resulted in a number of actions, in particular the following: (a) There is an urgent need of defining the concept of flexible working hours, since it has been used in many different and even counterintuitive ways; the most obvious distinction is where the influence over the working hours lies, that is between the “company-based flexibility” and the “individual-oriented flexibility”; (b) The review of the Legislation in force in the 15 European countries shows that the regulation of working times is quite extensive and covers (Council Directive 93/104/EC) almost all the various arrangements of working hours (i.e., part-time, overtime, shift, and night work), but fails to provide for flexibility; (c) According to the data of the Third EU Survey on Working Conditions, longer and “irregular” working hours are in general linked to lower levels of health and well-being; moreover, low (individual) flexibility and high variability of working hours (i.e., company-based flexibility) were consistently associated with poor health and well-being, while low variability combined with high autonomy showed positive effects; (d) Six substudies from different countries demonstrated that flexible working hours vary according to country, economic sector, social status, and gender; overtime is the most frequent form of company-based flexibility but has negative effects on stress, sleep, and social and mental health; individual flexibility alleviates the negative effects of the company-based flexibility on subjective health, safety, and social well-being; (e) The literature review was able to list more than 1,000 references, but it was striking that most of these documents were mainly argumentative with very little empirical data. Thus, one may conclude that there is a large-scale intervention ongoing in our society with almost completely unknown and uncontrolled effects. Consequently, there is a strong need for systematic research and well-controlled actions in order to examine in detail what flexible working hours are considered, what and where are their positive effects, in particular, as concerns autonomy, and what regulation seem most reasonable.     

Implications of flexible work systems for work studies

The relationship between changing work systems and work study methods is discussed by focusing on a recent trend toward more flexible work systems in different countries. These systems are commonly characterized by (a) uncoupling of working hours from business hours, (b) combining different atypical work forms and (c) individualized work patterns. Increased flexibility in working patterns is demanded because business hours may be covered by different workers and because special arrangements become necessary for unpopular shifts or linking separate jobs. Changes in work systems seem more successful when they are associated with (a) multiskilled work, (b) independent task implementation, (c) networked communication, (d) balanced or adjusted workload, and (e) accommodation of workers' preferences. Special attention is drawn to safety and health concerns and work-life effects. Many intervention studies done for work improvement are paying attention to multifaceted work aspects, locally available options, and participation by people. All these elements are important because prepackaged solutions do not exist. The following three views seem especially useful for action-oriented work studies: 1) Look at multiple aspects of the work, including work content and atypical work forms; 2) Know worker preferences and available options; and 3) Take into account work elements that may not be well defined, but important from local points of view. It is envisioned that these studies can provide support for a well-informed participatory process of work system changes in each local context.     

Protein rigidity and thermophilic adaptation

We probe the hypothesis of corresponding states, according to which homologues from mesophilic and thermophilic organisms are in corresponding states of similar rigidity and flexibility at their respective optimal temperatures. For this, the local distribution of flexible and rigid regions in 19 pairs of homologous proteins from meso- and thermophilic organisms is analyzed and related to activity characteristics of the enzymes by constraint network analysis (CNA). Two pairs of enzymes are considered in more detail: 3-isopropylmalate dehydrogenase and thermolysin-like protease. By comparing microscopic stability features of homologues with the help of stability maps, introduced for the first time, we show that adaptive mutations in enzymes from thermophilic organisms maintain the balance between overall rigidity, important for thermostability, and local flexibility, important for activity, at the appropriate working temperature. Thermophilic adaptation in general leads to an increase of structural rigidity but conserves the distribution of functionally important flexible regions between homologues. This finding provides direct evidence for the hypothesis of corresponding states. CNA thereby implicitly captures and unifies many different mechanisms that contribute to increased thermostability and to activity at high temperatures. This allows to qualitatively relate changes in the flexibility of active site regions, induced either by a temperature change or by the introduction of mutations, to experimentally observed losses of the enzyme function. As for applications, the results demonstrate that exploiting the principle of corresponding states not only allows for successful thermostability optimization but also for guiding experiments in order to improve enzyme activity in protein engineering.     

Sleeping on the Job during Night Shifts May Be Associated with Extended Night Shifts and/or Variable Night Shift Onset Times

Continuous rotating shiftworkers temporarily working overtime slept at least once during the working hours of their night shifts. They worked at an electric power distribution plant in São Paulo (Brazil). In order to detect factors that could be associated with sleeping on the job, we compared those who slept (sleep group – S) with those who did not sleep (non-sleep group – NS) as to the number of night shifts, the average length of night shifts, the variability in night shift onset and offset times and the length of sleep episodes at home between consecutive night shifts. Data collection was based on dairies filled in by the workers for 30 consecutive days. For both S and NS groups, the number of night shifts for each worker varied from 5 to 9, no difference being found between groups. Individual means of night shifts length varied from 9.4 ± 0.3 hr to 14.2 ± 0.6 hr; they were significantly longer in the S than in the NS group. Night shift onset times were shown to be significantly more variable in the S than in the NS group, whereas offset times did not differ significantly between groups. Length of sleep episodes at home was not significantly different between groups. Workers who slept on the job were those who had longer working bouts and / or more variable night shift onset times. Differences among workers may be due to individual strategies to cope with a situation in which the work schedule included night shifts that were much longer than the established 8 hours, and with many changes in onset times from one night shift to the next.     

Principles of flexible protein-protein docking

Treating flexibility in molecular docking is a major challenge in cell biology research. Here we describe the background and the principles of existing flexible protein-protein docking methods, focusing on the algorithms and their rational. We describe how protein flexibility is treated in different stages of the docking process: in the preprocessing stage, rigid and flexible parts are identified and their possible conformations are modeled. This preprocessing provides information for the subsequent docking and refinement stages. In the docking stage, an ensemble of pre-generated conformations or the identified rigid domains may be docked separately. In the refinement stage, small-scale movements of the backbone and side-chains are modeled and the binding orientation is improved by rigid-body adjustments. For clarity of presentation, we divide the different methods into categories. This should allow the reader to focus on the most suitable method for a particular docking problem.     

Body size and activity times mediate mammalian responses to climate change

Model predictions of extinction risks from anthropogenic climate change are dire, but still overly simplistic. To reliably predict at‐risk species we need to know which species are currently responding, which are not, and what traits are mediating the responses. For mammals, we have yet to identify overarching physiological, behavioral, or biogeographic traits determining species' responses to climate change, but they must exist. To date, 73 mammal species in North America and eight additional species worldwide have been assessed for responses to climate change, including local extirpations, range contractions and shifts, decreased abundance, phenological shifts, morphological or genetic changes. Only 52% of those species have responded as expected, 7% responded opposite to expectations, and the remaining 41% have not responded. Which mammals are and are not responding to climate change is mediated predominantly by body size and activity times (phylogenetic multivariate logistic regressions, P < 0.0001). Large mammals respond more, for example, an elk is 27 times more likely to respond to climate change than a shrew. Obligate diurnal and nocturnal mammals are more than twice as likely to respond as mammals with flexible activity times (P < 0.0001). Among the other traits examined, species with higher latitudinal and elevational ranges were more likely to respond to climate change in some analyses, whereas hibernation, heterothermy, burrowing, nesting, and study location did not influence responses. These results indicate that some mammal species can behaviorally escape climate change whereas others cannot, analogous to paleontology's climate sheltering hypothesis. Including body size and activity flexibility traits into future extinction risk forecasts should substantially improve their predictive utility for conservation and management.     

Machine Sharing in Manufacturing Systems: Total Flexibility versus Chaining

In this paper, we compare the operational performance of two machine-sharing configurations: total flexibility and chaining. We show that chaining captures most of the benefits of total flexibility while limiting the number of part types processed on any individual machine to only two. We examine the relative desirability of the two configurations under varying buffer sizes, loading conditions, number of machines, and setup times, as well as for different control policies. For nonzero setups times, we show that chained configurations can outperform fully flexible ones. This particularly is the case when either the number of machines or length of setup times is high. We also find that the effect of the system size on performance diminishes with the number of machines. This means that multiple smaller chains can perform almost as well as a single long one. Our results are consistent with the recent findings of Jordan and Graves (1995), who examined the economic benefits of chaining relative to full flexibility.     

Senior house officers in medicine: postal survey of training and work experience.

OBJECTIVES: To describe working conditions for senior house officers in medicine in Scotland and to relate these to the quality of clinical training they receive. DESIGN: Postal questionnaire survey. SUBJECTS: All senior house officers in medicine and related specialties in post in Scotland in October 1995 (n = 437); 252 (58%) respondents. MAIN OUTCOME MEASURES: Questionnaires covered hours, working patterns, measures of workload, an attitudes to work scale, and experience of education and training. RESULTS: In the week before the questionnaire, doctors on rotas had worked a mean of 7.4 (95% confidence interval 5.8 to 9.0) hours in excess of their contracts, compared with 3.7 (2.0 to 5.5) hours for those on partial shifts. The most common reason for this was "the needs of the patients or the service." Those on partial shifts reported significantly less continuity of care with patients than those on rotas (Mann-Whitney U test, z = -4.2, P < 0.0001) or full shifts (z = -2.08, P = 0.03). Doctors in general medicine reported significantly higher measures of workload (number of acute admissions, number of times called out, and fewest hours'' uninterrupted sleep) than those in subspecialties. Consultants'' clinical teaching and style of conducting a ward round were significantly related to factors extracted from the attitudes to work scale. CONCLUSIONS: The quality of senior house officers'' training is detrimentally affected by a variety of conditions, especially the need for closer support and supervision, the need for greater feedback, and the lack of time that consultants have to dedicate to clinical training. Efforts should be made to improve these conditions and to reinforce a close working relationship between trainee and supervising consultant.     

Employee control over scheduling of shifts and objectively measured working hour characteristics: a cross-sectional analysis of linked register and survey data

We aimed to study the association of perceived control over scheduling of shifts with objectively measured working hour characteristics in shift workers. The participants were 5128 hospital employees (91% women, 85% nursing personnel, average age 43 years) in period-based work (114:45h/3 weeks) from the 2015 Finnish Public Sector study. Survey responses to a measure of control over scheduling of shifts were linked to payroll data on working hour characteristics during the 91 days preceding the survey. We used multinomial logistic regression to assess differences in dichotomized proportion of working hour characteristics (being full-time worker, number of work shifts, long work weeks (>40h and >48h/week), long work shifts (>12-h), evening and night shifts, quick returns (<11h shift interval), single days off, weekend work, >4 consecutive work shifts, and variability of shift length with cut points at 10% or 25% between employees with high, intermediate, or low control over scheduling of shifts. Analyses were adjusted for age, sex, education, full-/part-time work (where applicable), duration of shift work experience, perceived work ability, children < 18 years in the household, and overall stressfulness of the life situation. Differences between age groups, men and women, and levels of work ability were examined using interaction terms. In adjusted analyses, the proportion of full-time workers was lower among employees with intermediate control over scheduling of shifts compared to those with high control (OR 0.78, 95% CI 0.61–0.98). High proportion (>25%) of weekend work was lower among employees with low control over scheduling of shifts compared to high control (OR 0.75, 95% CI 0.61–0.93). High proportion (>25%) of having >4 consecutive work shifts was associated with lower control over scheduling of shifts (OR 1.35, 95% CI 1.13–1.62). Variability of shift length was lower among employees with intermediate and low control over scheduling of shifts compared to those with high control (OR 0.78, 95% CI 0.66–0.93; OR 0.62, 95% CI 0.51–0.75, respectively). No association was observed between the level of control over scheduling of shifts and high proportion of long work weeks (>25% of >40h weeks and >10% of >48h weeks), long work shifts (>25%), quick returns (>25%), single days off (>25%), and evening or night shifts (>10%) in the whole sample. In subgroup analyses, women with low control over scheduling shifts had lower odds ratio (OR 0.58, 95% CI 0.37–0.91) and men had higher odds ratio (OR 2.97, 95% CI 1.26–6.98) for large proportion of >12-h shifts. In conclusion, the employees with high control over scheduling of shifts had slightly more often unsocial working hour characteristics than those with intermediate or low control over scheduling of shifts. The findings, however, suggest that good work time control in shift work can be possible without compromising shift ergonomics.     

Under what conditions signal transduction pathways are highly flexible in response to external forcing? A case study on calcium oscillations

Sensitivity and flexibility are typical properties of biological systems. These properties are here investigated in a model for simple and complex intracellular calcium oscillations. In particular, the influence of external periodic forcing is studied. The main point of the study is to compare responses of the system in a chaotic regime with those obtained in a regular periodic regime. We show that the response to external signals in terms of the range of synchronization is not significantly different in regular and chaotic Ca2+ oscillations. However, both types of oscillation are highly flexible in regimes with weak dissipation. Therefore, we conclude that dissipation of free energy is a suitable index characterizing flexibility. For biological systems this appears to be of special importance since for thermodynamic reasons, notably in view of low free energy consumption, dissipation should be minimized.     

Balancing flexibility for the employer and the employee: a case study of the development of annualized hours employment contracts

As with many forms of flexible working, Annualized Hours (AH) systems offer potential benefits to both the employer and the employee. However, the flexibility requirements of employers and employees often conflict. Therefore, when a large food manufacturing organization decided to redesign its AH system, it employed an independent consultancy to act as neutral third party. The consultancy provided technical expertise and assistance in developing an AH system that optimised productivity and was acceptable to the workforce. Data are presented, obtained from focus groups conducted throughout the organization, describing some of the potential difficulties of implementing an AH system. Drawing upon these data, a number of new AH systems were proposed and modelled using specialist software tools. The design process is described, together with the advantages and difficulties associated with use of the software tools. It is concluded that the key elements in the process of designing AH systems are centred around issues of trust and communication; the involvement of a broad range of interested parties, through a process of carefully managed group facilitation; and the need for adequate technical support in the development and evaluation of AH systems.