A Flexible Evaluative Framework for Order Picking Systems

This paper develops a novel framework to evaluate the integral performance of order picking systems with different combinations of storage and order picking policies. The warehousing literature on order picking mostly considers minimizing either elapsed time or distance as the sole objective, whereas warehouse managers in a supply chain have to look beyond single‐dimensional performance and consider trade‐offs among different criteria. Thus managers still need a unified and efficient framework to select a portfolio of appropriate order picking policies from a multi‐criteria and contextual perspective. Our framework—combining data envelopment analysis, ranking and selection, and multiple comparisons—provides an efficient methodology to simultaneously analyze several interrelated problems in order picking systems with multiple performance attributes, such as service levels and operational costs. We demonstrate our approach through comprehensive evaluations of order picking policies in three low‐level, picker‐to‐parts rectangular warehouses facing demand variations.     

Scheduling Truck Arrivals at an Air Cargo Terminal

We consider the scheduling of truck arrivals at an air cargo terminal. By coordinating arrivals of cargo delivery trucks with outbound flight departure schedules, some of the shipments can be transferred directly to the departing flights, while others will be stored at the terminal's storage facility and incur extra handling and storage costs. The objective is to obtain a feasible schedule so as to minimize the total cost of operations. We formulate the problem as a time‐indexed integer program and show that, even with limited number of unloading docks at the terminal, the problem is non‐trivial (NP‐hard in the strong sense). Our solution method includes an exact solution procedure to determine an optimal unloading sequence for the shipments carried by each truck, together with a Lagrangian relaxation‐based heuristic for assigning trucks to truck docks and determining truck arrival times. We conducted computational experiments to test the performance of our solution method. Computational results show that our method can generate near‐optimal solutions efficiently. Our simulation results indicate that the scheduling approach proposed in this paper has the potential to generate significant cost savings over a first‐come, first‐served approach currently used at the air cargo terminal that we observed.     

Self-management competencies in self-managing teams: Their impact on multi-team system productivity

This research examined how composition of individual capabilities within self-managed teams translates into greater effectiveness for multi-team systems (MTS) in which teams are embedded. We investigated how a broad range of self-management competencies by team members aggregate to form a collective construct that influences productivity of a team network. In a semiconductor plant, we surveyed 716 members from 97 self-managed teams in 21 MTS. We found that MTS comprising teams whose members widely practice self-management strategies attain higher productivity gains and that multi-team systems consisting of highly cohesive teams of self-managers are the most productive.     

An Examination of the Relationship Between Absorptive Capacity and Organizational Learning,and a Proposed Integration

Since its inception, the concept of absorptive capacity has been closely linked with notions of organizational learning. Yet the precise nature of the relationship between these two concepts has never been established. This relationship is examined in a variety of ways, and it is suggested that the literature on these two concepts shares a conceptual affinity which needs to be delineated. It is suggested that absorptive capacity (a dynamic capability) is a concrete example of organizational learning that concerns an organization's relationship with new external knowledge. Using the 4I Model for organizational learning ( Crossan, M.M., Lane, H.W. and White, R.E. (1999 ). An organizational learning framework: from intuition to institution. Academy of Management Review, 24, 522–537) and Zahra and George's conceptualization of absorptive capacity ( Zahra, S.A. and George, G. (2002 ). Absorptive capacity: a review, reconceptualization, and extension. Academy of Management Review, 27, 185–203), this paper proposes an integration of the two concepts.     

When do Public Managers Imitate Each Other? Mimetic Decision Making in Contracting Decisions of Danish Municipalities

Using organizational new institutional theory, this paper explores a core mechanism underlying contracting decisions in public organizations. A central proposition of this branch of institutional theory is that uncertainty leads to organizational isomorphism. The present study investigates this proposition by asking: When does perceived uncertainty lead public managers to imitative behavior in contracting out decisions? Contrary to most previous studies, we apply an individual level approach and relate different types of perceived uncertainty of decision makers to mimetic decision making. We define mimetic decision making as when decision makers deliberately obtain information about other organizations in order to possibly imitate them. In a survey of Danish municipal managers facing important and complex contracting decisions, we test our hypotheses about three types of perceived uncertainty and mimetic decision making. The results show that technological uncertainty is strongly related to mimetic decision making among public managers. However, we do not find significant results for either volume uncertainty or performance uncertainty. The paper illustrates how uncertainty, through mimetic decision making, is connected to organizational isomorphism. It further highlights that future studies should pay attention to the multidimensionality of uncertainty and its consequences.     

Changing default risk dependencies during the subprime crisis: DJ iTraxx subindices and goodness-of-fit-testing for copulas

This paper tests whether (and to what extent) default risk dependencies changed during the subprime crisis in 2007 and 2008. This is done by applying a Goodness-of-fit test, based on the Rosenblatt transformation, to test various null hypotheses with respect to the copula function that describes the stochastic dependence between daily returns of six sector-specific subindices of the Dow Jones iTraxx Credit Default Swap index for Europe. Overall, the results suggest that in the bivariate case, the t-copula is a better approximation to the true copula of returns of DJ iTraxx subindices than the normal copula or the generalized Clayton copula. On average, the number of degrees of freedom of the bivariate t-copula tends to decrease during the crisis. As expected, the correlation between the returns of the subindices increases significantly during the crisis. However, the multivariate analysis reveals that it is only before the crisis that the null hypothesis of a six-dimensional t-copula is not rejected. During the crisis, the multivariate stochastic dependence between the sector-specific DJ iTraxx subindices seems to change in such a complex way that it is no longer sufficiently described by a multivariate t-copula.     

It’s Not What You Know, but How You Use It: Statistical Knowledge and Adolescent Problem Gambling

This paper examined the nature of irrational gambling-related cognitions in a sample of 926 adolescents (mean age = 14.5 years) sampled from Australian schools. Students were differentiated according to gambling status and administered a series of items that assessed their understanding of objective odds, the nature of randomness, the role of skill in gambling, and the perceived profitability of gambling. The results confirmed previous findings that problem gamblers tend to be more irrational in their perceptions, as indicated by stronger beliefs in the role of skilful play in chance activities, and that gambling is a potentially profitable activity. However, counter intuitively, problem gamblers did not appear to have any poorer understanding of objective probabilities. These results are discussed in terms of Sevigny and Ladouceur’s (2004) concept of cognitive switching as well as psychological research concerning the role of emotional and motivational factors in the development of an illusion of control. The implications of these findings for gambling education programs are discussed.