Concerning Workload Control and Order Release: The Pre‐Shop Pool Sequencing Decision

Every production planning concept that incorporates controlled order release will initially withhold jobs from the shop floor and create a pre‐shop pool. Order release is a key component of the Workload Control concept that aims to maintain work‐in‐process within limits while ensuring due dates are met. Order release includes two decisions: (i) a sequencing decision that establishes the order in which jobs are considered for release; and, (ii) a selection decision that determines the criteria for choosing jobs for release. While selection has received much research attention, sequencing has been largely neglected. Using simulation, this study uncovers the potential for performance improvement in the sequencing decision and improves our understanding of how order release methods should be designed. Although most prior studies apply time‐oriented sequencing rules and load‐oriented selection rules, analysis reveals that load balancing considerations should also be incorporated in the sequencing decision. But an exclusive focus on load balancing is shown to increase mean tardiness and, paradoxically, require high workloads. A new sequencing rule is developed that only balances loads when multiple orders become urgent. It avoids high mean tardiness and allows the shop to operate at a low workload level. At the same time, the percentage tardy is reduced by up to 50% compared to a purely time‐oriented rule. The findings have implications not only for Workload Control but for any concept that features order release control, such as ConWIP and Drum‐Buffer‐Rope.     

Die Wirkung von informellen und internetbasierten Rekrutierungskanälen auf den Rekrutierungserfolg: Eine empirische Analyse in kleinen und mittleren Unternehmen

This study analyses the impact of informal and web-based recruitment sources on several dimensions of SME recruitment success. Our results show that informal recruitment sources unfold a different impact on applicant-pool quantity and -quality, and applicant fit than web-based recruitment sources. Informal recruitment sources (recruitment via personal networks, employee referrals etc.) enhance applicant-pool quality, person-organization fit and person-job fit. Web-based recruitment sources primarily increases applicant-pool quantity. HR-recruitment websites also unfold a positive effect on applicant-pool quality. Accordingly, the use of these recruitment sources needs to be planned in a strategic manner, in order to achieve firm specific recruitment goals regarding applicant-pool quantity and –quality.     

Lean Control for Make‐to‐Order Companies: Integrating Customer Enquiry Management and Order Release

A lead time that is short, predictable, and reliable is an increasingly important criterion in supplier selection. Although many companies may achieve this through lean implementation, high‐variety manufacturers, for example, small and medium‐sized make‐to‐order companies, have found that lean's planning and control techniques do not apply. This article outlines a planning and control concept known as workload control (WLC) that integrates customer enquiry management, including a due‐date setting rule, with order release control. Simulation is then used to assess its impact on shop performance. Results demonstrate that an integrated WLC concept can reduce the percentage of tardy jobs—so short lead times can be realistically quoted—while also reducing and stabilizing workloads. WLC can level demand and production over time when work is not standardized and it is not possible to synchronize flows on the shop floor. Results are shown to be robust to changes in routing characteristics, the mix of orders with due dates specified by the customer and proposed internally, and the strike rate (or order‐winning probability). Hence, an integrated approach to WLC represents an important step toward achieving lean in make‐to‐order companies.     

Asymptotics of improved generalized moment estimators for spatial autoregressive error models

Abstract

This article considers linear models with a spatial autoregressive error structure. Extending Arnold and Wied (2010) Arnold, M., Wied, D. (2010). Improved GMM estimation of the spatial autoregressive error model. Econ. Lett. 108:65–68.[Crossref], [Web of Science ®] , [Google Scholar], who develop an improved generalized method of moment (GMM) estimator for the parameters of the disturbance process to reduce the bias of existing estimation approaches, we establish the asymptotic normality of a new weighted version of this improved estimator and derive the efficient weighting matrix. We also show that this efficiently weighted GMM estimator is feasible as long as the regression matrix of the underlying linear model is non stochastic and illustrate the performance of the new estimator by a Monte Carlo simulation and an application to real data.     

Independence in Contingency Tables Using Simplicial Geometry

Frequently, contingency tables are generated in a multinomial sampling. Multinomial probabilities are then organized in a table assigning probabilities to each cell. A probability table can be viewed as an element in the simplex. The Aitchison geometry of the simplex identifies independent probability tables as a linear subspace. An important consequence is that, given a probability table, the nearest independent table is obtained by orthogonal projection onto the independent subspace. The nearest independent table is identified as that obtained by the product of geometric marginals, which do not coincide with the standard marginals, except in the independent case. The original probability table is decomposed into orthogonal tables, the independent and the interaction tables. The underlying model is log-linear, and a procedure to test independence of a contingency table, based on a multinomial simulation, is developed. Its performance is studied on an illustrative example.     

Gender inequality in the one percent: A look under the hood of high incomes in Germany

Gender differences in economic outcomes are important topics in social science research. However, the study of gender differences among economic elites—“the top one percent”—has received surprisingly little attention, likely also due to a lack of empirical data. This paper investigates gender differences in individual and household income among the top one percent of individual monthly net incomes and top two percent of net household incomes using data from the German Microcensus from 2006 to 2016 covering more than 3.3 million individuals. I find that women account for only around 14% of the one percent in individual incomes. Additionally, regarding the household level, women's incomes are sufficient to achieve two percent status in fewer than 10% of all households. Both numbers did hardly change over the decade from 2006 to 2016. Furthermore, women's pathways to belonging to a high-income household are far more dependent on their partner's education and employment status than men's. Overall, the findings thus show dramatic gender differences among the German economic elite that do not narrow over time.     

The Imperial Origins of Nation-States: Revisiting Hannah Arendt's Genealogy of Totalitarianism1

Against the backdrop of World War II, Hannah Arendt explores the origins of totalitarian rule, arguing that they date back to as early as the late nineteenth century. Alongside anti-Semitism, overseas colonialism and pan-nationalism paved the way for the totalitarian regimes that crystallized a few decades later by weakening the system of nation-states from within. Using the example of Germany, I will argue in this article that we need to revise Arendt's narrative. It focuses too narrowly on how nationalism turned into its categorical opposite, imperialism, neglecting the complementary dynamics of how empire facilitated the nation-state. Only then can we acknowledge the deep rupture that World War I brought about when it created in its wake a dynamic that culminated in the destruction of European nation-states.