The no-wait job shop with regular objective: a method based on optimal job insertion

The no-wait job shop problem (NWJS-R) considered here is a version of the job shop scheduling problem where, for any two operations of a job, a fixed time lag between their starting times is prescribed. Also, sequence-dependent set-up times between consecutive operations on a machine can be present. The problem consists in finding a schedule that minimizes a general regular objective function. We study the so-called optimal job insertion problem in the NWJS-R and prove that this problem is solvable in polynomial time by a very efficient algorithm, generalizing a result we obtained in the case of a makespan objective. We then propose a large neighborhood local search method for the NWJS-R based on the optimal job insertion algorithm and present extensive numerical results that compare favorably with current benchmarks when available.     

Lust an der Macht – Frauen in Organisationen

Storyline and analysis of the film “The Devil Wears Prada” provide vivid scenes to derive reflections on organisational culture in globalised companies and women in chief positions. Women come into conflict with leading the company successfully, the dependence on efficient – female – staff and the image as a woman. The article illustrates, how influences of the company’s products fashion und fashion market have a normative effect, especially on female staff members. Theories of organisational culture, careers of women and findings of gender research are shown in connection with complex strategies of women in their determination to succeed, to self-realization and the pressure to adapt oneself. This involves reflected perspectives to leave clichés of gender and to reinforce organisational and personal potentials.     

An integrative model of leadership behavior

Decades of questionnaire and interview studies have revealed various leadership behaviors observed in successful leaders. However, little is known about the actual behaviors that cause those observations. Given that lay observers are prone to cognitive biases, such as the halo effect, the validity of theories that are exclusively based on observed behaviors is questionable. We thus follow the call of leading scientists in the field and derive a parsimonious model of leadership behavior that is informed by established psychological theories. Building on the taxonomy of Yukl (2012), we propose three task-oriented behavior categories (enhancing understanding, strengthening motivation and facilitating implementation) and three relation-oriented behavior categories (fostering coordination, promoting cooperation and activating resources), each of which is further specified by a number of distinct behaviors. While the task-oriented behaviors are directed towards the accomplishment of shared objectives, the relation-oriented behaviors support this process by increasing the coordinated engagement of the team members. Our model contributes to the advancement of leadership behavior theory by (1) consolidating current taxonomies, (2) sharpening behavioral concepts of leadership behavior, (3) specifying precise relationships between those categories and (4) spurring new hypotheses that can be derived from existing findings in the field of psychology. To test our model as well as the hypotheses derived from this model, we advocate the development of new measurements that overcome the limitations associated with questionnaire and interview studies.     

Separator-based data reduction for signed graph balancing

Polynomial-time data reduction is a classical approach to hard graph problems. Typically, particular small subgraphs are replaced by smaller gadgets. We generalize this approach to handle any small subgraph that has a small separator connecting it to the rest of the graph. The problem we study is the NP-hard Balanced Subgraph problem, which asks for a 2-coloring of a graph that minimizes the inconsistencies with given edge labels. It has applications in social networks, systems biology, and integrated circuit design. The data reduction scheme unifies and generalizes a number of previously known data reductions, and can be applied to a large number of graph problems where a coloring or a subset of the vertices is sought. To solve the instances that remain after reduction, we use a fixed-parameter algorithm based on iterative compression with a very effective heuristic speedup. Our implementation can solve biological real-world instances exactly for which previously only approximations were known. In addition, we present experimental results for financial networks and random networks.     

Hierarchische Planung für industrielle Logistikdienstleister

In this paper a planning and control system for logistics service providers (called LPS system) is developed under consideration of their specific flexibility potentials. Due to the complexity of such planning decisions (different planning levels and data quality of these levels as well as time horizons etc.), a multi-stage, hierarchical planning system is proposed which minimizes the relevant costs under consideration of the flexibilities. The advantage of a hierarchical planning concept consists in a limited planning complexity because otherwise data collection and solution development would lead to unsolvable problems in practice. The results of using LPS systems for a real-life case show a significant pay-off for logistics service providers due to the remarkable cost savings by applying a hierarchical planning concept.     

Developments in implicit leadership theory and cognitive science: Applications to improving measurement and understanding alternatives to hierarchical leadership

After reviewing key findings regarding leadership categorization theory, we develop new perspectives regarding the design of behavioral measures of leadership and the implications of shared leadership and complex adaptive leadership conceptualizations of leadership. In particular, by applying recent developments in cognitive science, we explain how an understanding of symbolic, connectionist, and embodied representations of knowledge can benefit behavioral measures of leadership. Additionally, we address some practical issues associated with the measurement of leadership and argue that ratings which tap episodic memory at the event level may be more meaningful than ratings based on semantic memory. Finally, we discuss how notions of shared leadership and of leaders as catalysts for complexity can create unique complications for leadership perceptions, coordinated behavior within a group, and the measurement of leadership.     

Measuring operational excellence: an operational excellence profitability (OEP) approach

The pursuit of operational excellence in the manufacturing industry is at rise but its measurement still lacks of appropriate indicators to determine its financial benefits. The ambiguity is due to the impact arisen from manufacturing fluctuations such as price and cost, production mix and direct and indirect parameters variations. Manufacturing fluctuations distort the cost benefit of operational excellence. This paper, therefore, proposes the OEP (Operational Excellence Profitability) indicators to isolate the impact of manufacturing fluctuation and distinctly identify the payback of operational excellence strategies and initiatives through cost benefits of achieving higher efficiency and yield. The paper presents the conceptual and mathematical development of the proposed OEP indicators and the formulas used for their calculation. Hypothetical and industrial-based investigations and applications of the OEP indicators are conducted for their validation. The results obtained from the hypothetical exercise and industrial case suggest that OEP indicators can provide an effective cost-benefit analysis of operational excellence. This would contribute in providing manufacturing organizations with more complete information regarding the performance of their processes, which will allow their directors and managers to take better decisions related to the management and improvement of their processes.     

Federal budget helps drive health policy. A close-up look at the budget process and how it affects health care funding

Crafting the budget is an annual process that Congress and the administration use to define the national policy agenda. It is a massive undertaking to decide how more than two trillion dollars is spent by the federal government. Over 20 percent of the budget is used for health care. The budget is a political document that defines the priorities of the federal government and directly influences overall health policy. Its construction deserves to be followed and influenced by physicians to ensure the health of the public.     

Leadership déjà vu all over again

Much leadership literature neglects its historical-contextual antecedents and as a result over-emphasizes zeitgeist, or tenor of the time's social forces. This neglect impedes leadership research by encouraging academic amnesia and promoting a strong feeling of research déjà vu among many researchers and practitioners. In this article, we develop a leadership historical-contextual superstructure consisting of evolutionary antecedents, paradigmatic antecedents, purpose and definitional antecedents, stakeholder antecedents, levels of analysis and temporal antecedents, and research dissemination antecedents. We use this superstructure to analyze current work in the increasingly important relational leadership research stream to illustrate how the superstructure's use can aid leadership researchers and practitioners in avoiding leadership déjà vu and academic amnesia and help build a more cumulative field.