Harald Dyckhoff

A typology of cutting and packing problems

Abstract Cutting and packing problems appear under various names in literature, e.g. cutting stock or trim loss problem, bin or strip packing problem, vehicle, pallet or container loading problem, nesting problem, knapsack problem etc. The paper develops a consistent and systematic approach for a comprehensive typology integrating the various kinds of problems. The typology is founded on the basic logical structure of cutting and packing problems. The purpose is to unify the different use of notions in the literature and to concentrate further research on special types of problems.

Measuring ecological efficiency with data envelopment analysis (DEA)

Abstract The measurement of ecological efficiency provides some important information for the companies’ environmental management. Ecological efficiency is usually measured by comparing environmental performance indicators. Data envelopment analysis (DEA) shows a high potential to support such comparisons, as no explicit weights are needed to aggregate the indicators. In general, DEA assumes that inputs and outputs are ‘goods’, but from an ecological perspective also ‘bads’ have to be considered. In the literature, ‘bads’ are treated in different and sometimes arbitrarily chosen ways. This article aims at the systematic derivation of ecologically extended DEA models. Starting from the assumptions of DEA in production theory and activity analysis, a generalisation of basic DEA models is derived by incorporating a multi-dimensional value function f . Extended preference structures can be considered by different specifications of f , e.g. specifications for ecologically motivated applications of DEA.

The concept of joint production and ecological economics

Joint production is suggested as one of the conceptual foundations of ecological economics. The notion of joint production springs immediately from the application of thermodynamics, and has a long history in economic analysis. Considerations of joint production give rise to philosophical concerns relating to responsibility and knowledge. The concept of joint production is easily comprehensible, and is also constitutive and supportive of a range of concepts current in ecological economic thought.

The Expansion of Supply Chains to Closed Loop Systems: A Conceptual Framework and the Automotive Industry’s Point of View

An environmental orientated supply chain management (SCM) should not be limited to SCM processes, but instead include the analysis of recycling processes as well, for example reverse logistic aspects. Consequently, SCM must be expanded to closed loop management (CLM). In this paper, we discuss the theoretical and practical backgrounds of CLM, presenting a “double-layer closed loop model” and analyzing the example of the automotive cycle.

Sicherstellung der Effektivität und Effizienz der Führung als Kernfunktion des Controlling

ZusammenfassungDie Sicherstellung der Effektivität und Effizienz der Führung kann als Wesensmerkmal des rationalitätsorientierten Controlling sowie als Kernfunktion auch anderer Controlling-Konzeptionen verstanden werden.Dem in diesem Kontext vorherrschenden Begriffswirrwarr lässt sich durch die Ableitung einer präzisen und zum Üblichen Sprachgebrauch in Wissenschaft und Praxis weitestgehend kompatiblen Definition der Begriffe Effektivität und Effizienz entgegenwirken.Zur Messung von Effizienz steht mit der Data Envelopment Analysis ein produktionstheoretisch fundiertes Instrument zur VerfÜgung, das sich in jüngerer Zeit auch im deutschen Sprachraum zunehmender Verbreitung erfreut.Übertriebenen Hoffnungen auf die Möglichkeiten eines zwischenbetrieblichen Benchmarking ist allerdings aufgrund theoretischer Grenzen empirischer Effizienzvergleiche entgegenzutreten.

Theoretische Begründung einer Effizienzanalyse mittels Data Envelopment Analysis (DEA)

SummaryData Envelopment Analysis (DEA) is a collection of models measuring the relative efficiency of Decision Making Units with linear programming techniques. This paper examines the foundations of DEA in the theory of production and in Multiple Criteria Decision Making to point out its possibilities and limitations. Activity analysis is chosen as the theoretical frame to describe the problem and to derive a basic DEA model. The systematic approach and the consideration of MCDMknowledge lead to a sharper identification of the general DEA-axioms and the characteristics of basic DEA models. Finally, a constructive criticism provides useful hints for extensions and generalizations of DEA.

Measuring balanced effectiveness and efficiency of German business schools’ research performance

The selection, aggregation and analysis of research performance data acquired by the Centre for Higher Education (CHE) as well as its assessment method identifying leading research business schools are controversially discussed in literature and praxis. Data Envelopment Analysis (DEA) provides an alternative method to aggregate research performance data. Thereby however, business schools can achieve high effectiveness or efficiency scores by taking into account only some and not all indicators considered as relevant, resulting in an incomplete picture of business schools’ research performance. In this paper we therefore measure and analyze a new key performance indicator, the balance score respective the specialization degree of a business school by using the new method Balanced-DEA. This indicator reflects to which extent the research performance of a business school is balanced or specialized relative to predefined virtual balanced reference points.

Empirische Produktionsfunktion betriebswirtschaftlicher Forschung: Eine Analyse der Daten des Centrums für Hochschulentwicklung

ZusammenfassungDas Centrum für Hochschulentwicklung (CHE) erhebt umfassend Daten in Forschung und Lehre, um mehr Transparenz über die Leistungen der Hochschulen zu schaffen. Diese Daten repräsentieren aus produktionstheoretischer Sicht eine Technologie, deren effizienter Rand eine empirische Produktionsfunktion darstellt. Der Beitrag analysiert exemplarisch die Daten des CHE-Forschungsrankings 2005 für die Betriebswirtschaftslehre. Ein in seiner Deutlichkeit überraschender empirischer Befund besagt, dass im Bereich normaler Betriebsgrößen betriebswirtschaftlicher Fachbereiche von etwa 20 bis 50 Wissenschaftlern oder 8 bis 16 Professuren nahezu konstante Forschungsskalenerträge vorliegen, wenn diese gemäß CHE durch Publikationspunkte, Promotionshäufigkeiten und Drittmittelausgaben gemessen werden.SummaryReturns to scale are of particular importance for the optimal size of productive units. In this study the relationship between the size of German faculties of business economics and their research performance is determined. On the basis of a dataset, derived from data of Centrum für Hochschulentwicklung (Centre for Higher Education Development), the returns to scale are analyzed using production theory and Data Envelopment Analysis. In this context the research returns are measured by publications, dissertations and third-party funds. The empirical results show nearly constant returns to scale in the range of 8 to about 16 professors, and 20 to 50 scientists, respectively. Furthermore, the analysis of the data reveals that methodological problems may occur if conclusions regarding returns to scale are extracted exclusively from either input- or output-oriented DEA models.

Die Relevanz von Drittmittelindikatoren bei der Beurteilung der Forschungsleistung im Hochschulbereich

Welche Unis sind die besten Deutschlands? Mit dem Ziel, auf diese Frage eine Antwort zu liefern, werden von verschiedenen Zeitungen und Magazinen, wie Die Zeit, Focus, Spiegel und Wirtschaftswoche, regelmasig Hochschulrankings herausgegeben. Diese werden mit verschiedenen Methoden erstellt. So werden Befragungen von Studierenden, Professoren und Unternehmensverantwortlichen durchgefuhrt, aber auch quantitative Indikatoren erhoben. Die Analysen fuhren nicht selten zu unterschiedlichen Ergebnissen und werden daher vielfach kontrovers diskutiert.

A flexible concept for decision support: Evaluation and selection of suitable product development activities

Abstract Because of pragmatic reasons actual decision behaviour often differs from rationality requirements of decision theory. Against this background, a new concept for decision support has been developed opening up the opportunity to choose between different levels of evaluation. The characteristic feature of the proposed concept is its foundation in rationality postulates of decision theory while considering pragmatic requirements simultaneously. Thereby, the concept must be perceived as a frame within which the decision process may be formed in a flexible way. It has been drawn up and is presented in connection with the development of a decision support system (DSS) for comparative evaluation and selection of product development activities.