A generalized single product and single period problem with nonlinear parameters

K. Luo, L. KERBACHE, M. Menezes, C. VAN DELFT

International Transactions in Operational Research

mai 2012, vol. 19, n°3, pp.421-433

Départements : Information Systems and Operations Management, GREGHEC (CNRS)

Mots clés : Optimization, Perishable items, Production, Supply chain management

In this paper, we extend the study of the classical single-period newsboy inventory problem by considering Q1 costs that are non-linear functions of the decision variable. We assume that the demand probability density function is known to the decision maker.We prove that, under some much more relaxed conditions, the total expected profit function remains concave and classical optimization methods can thus be used to get the global optimal solution. After that, we provide numerical examples for illustrative purpose

A Petri Net Approach to Mediation-aided Composition of Web Services


IEEE Transactions on Automation Science and Engineering

2012, vol. 9, n°2, pp.429-435

Départements : Information Systems and Operations Management, GREGHEC (CNRS)

Cognitive Absorption and Trust for Workplace Collaboration in Virtual Worlds: An Information Processing Decision Making Perspective

S. C. SRIVASTAVA, S. Chandra, Y-L. Theng

Journal of the Association for Information Systems (JAIS)

octobre 2012, vol. 13, n°10, pp.797-835

Départements : Information Systems and Operations Management, GREGHEC (CNRS)

Virtual worlds (VWs) are media-rich cognitively engaging technologies that geographically dispersed organizations can use as a cost effective workplace collaboration tool. Using an information processing decision making perspective and building on unique characteristics of VWs, this paper proposes a nomological net for adaptive use intention (AUI) of VWs for workplace collaborations. AUI implies intention to use a technology in a setting different from the one for which it was initially designed. We study the AUI of VWs as a workplace collaboration tool which were originally conceived as recreational gaming platforms. Decision-making literature directs us to reduction of perceived cognitive burden and minimization of risk as the two key motivations for VWs' AUI. Building on these motivations, the paper identifies cognitive absorption and user trust in VWs as the mechanisms leading to individual-level AUI decision. Drawing on social cognitive theory and literature on trust, the proposed model not only re-specifies the concept of cognitive absorption in the context of VWs but also relates it to the level of trust and usage intention for VWs. We empirically tested the proposed model via data collected from 197 VW users in Singapore. Results demonstrate the significant roles that cognitive absorption' and user trust play in VW's usage as a collaboration tool. Further, through a series of post-hoc analyses, we demonstrate the imperative need for considering both cognitive absorption and user trust together in the proposed research model for theoretical parsimony. We also discuss implications for research and practice emerging out of this study.

Contract Performance in Offshore Systems Development: Role of Control Mechanisms


Journal of Management Information Systems

été 2012, vol. 29, n°1, pp.115-158

Départements : Information Systems and Operations Management, GREGHEC (CNRS)

Mots clés : Contract performance, Control mechanisms, Control modes, Control theory, Interaction effects, Offshoring, Outsourcing, Project governance, Softwaredevelopment

Although control theory has often been invoked to explain the coordination between client and vendor for information systems development ISD, insights into its moderating effects for explicating ISD contract performance, especially in the offshore context, is rather limited. Such insights would enable better understanding of variables that have complementary or substitutive effects on performance. Further, the control literature talks about different control modes e.g., formal and informal control modes classified as behavior, outcome, clan, and self-control modes without adequately distinguishing among the different control mechanisms enacting each of the control modes. In this research, by explicitly classifying the distinctions that exist within each of the control modes, we uncover the key role played by mechanistic governance in outsourced ISD. Grounding our arguments in the information requirement for performance evaluation, the study theorizes the moderating influence of mechanistic governance on the relationships of contract specificity and relational governance with ISD quality and cost performance. We test the theorized model in a field study comprising 160 offshore ISD projects executed by Indian vendors. Our results establish the significant complementary role of mechanistic governance on the relationships of contract specificity with both cost and quality performance variables. Further, mechanistic governance substitutes the impact of relational governance on cost performance. Thus, the study theoretically as well as empirically establishes the need for conceptualizing mechanistic governance as a viable and significant governance mechanism for offshore ISD contracts. The study also teases out the distinctions between the two prime contract types in vogue for managing offshore ISD contracts, namely, fixed price and time and materials contracts. The study thus contributes not only to control theory but also to the stream of literature examining offshore ISD contracts. Further, the study provides insights to managers on having well-specified contracts and acknowledging the role of mechanistic governance for better performance.

Key Resources and Internationalization Modes of Creative Knowledge-Intensive Business Services: The Case of Design Consultancies

C. Abecassis-Moedas, S. BEN MAHMOUD-JOUINI, C. Dell'Era, D. Manceau, R. Verganti

Creativity and Innovation Management

septembre 2012, vol. 21, n°3, pp.315-331

Départements : Information Systems and Operations Management, GREGHEC (CNRS)

In the 'knowledge economy', knowledge-intensive business services (KIBS) are a key driver for innovation and competitiveness. The internationalization of these businesses raises challenges given their specificities such as knowledge intensity, the importance of customer interaction and intimacy in service delivery. This paper focuses on design consultancies as a specific type of creative KIBS for which these characteristics are emphasized. The objective of this research is to analyse the resources leveraged by the firms to compete internationally. It is based on 11 case studies of design consultancies located in five different countries (France, Italy, Portugal, Spain and the UK) that were selected for their capacity to perform at the international level for several years. The paper advances three internationalization modes depending on contingent variables and focusing on specific resources that enable international competitiveness: star-based, process-based and glocality-based. In star-based creative KIBS, the individual designer has developed a reputation that attracts customers internationally, operating as a brand. In process-based creative KIBS, the reputation of a collective creative process attracts clients from other countries. In glocality-based creative KIBS, the geographical proximity obtained by opening international offices helps to develop a close understanding of the client through frequent interactions, and also to know the client's market well and to better understand local codes and signs. These modes complement those presented in the existing internationalization literature which takes the peculiarities of creative KIBS into consideration.

Revenue Management with End-of-Period Discounts in the Presence of Customer Learning


Production and Operations Management

2012, vol. 21, n°1, pp.69-84

Départements : Information Systems and Operations Management

Staffing a call center with uncertain non-stationary arrival rate and flexibility

S. Liao, G. Koole, C. VAN DELFT, O. Jouini

OR Spectrum

juillet 2012, vol. 34, n°3, pp.691-721

Départements : Information Systems and Operations Management, GREGHEC (CNRS)

Mots clés : Call centers, Uncertain arrival rate parameters, Staffing, Newsboy model, Stochastic programming, Robust programming

We consider a multi-period staffing problem in a single-shift call center. The call center handles inbound calls, as well as some alternative back-office jobs. The call arrival process is assumed to follow a doubly non-stationary stochastic process with a random mean arrival rate. The inbound calls have to be handled as quickly as possible, while the back-office jobs, such as answering emails, may be delayed to some extent. The staffing problem is modeled as a generalized newsboy-type model under an expected cost criterion. Two different solution approaches are considered. First, by discretization of the underlying probability distribution, we explicitly formulate the expected cost newsboy-type formulation as a stochastic program. Second, we develop a robust programming formulation. The characteristics of the two methods and the associated optimal solutions are illustrated through a numerical study based on real-life data. In particular we focus on the numerical tractability of each formulation. We also show that the alternative workload of back-office jobs offers an interesting flexibility allowing to decrease the total operating cost of the call center.

State Dependent Models of Material Handling Systems in Closed Queueing Networks

J. MacGregor Smith, L. KERBACHE

International Journal of Production Research

janvier 2012, vol. 50, n°2, pp.461-484

Départements : Information Systems and Operations Management, GREGHEC (CNRS)

Mots clés : Materials handling, Performance analysis, Queueing networks

A comprehensive algorithmic analysis of finite state-dependent queueing models and exponentially distributed workstations is formulated and presented. The material handling system is modeled with finite statedependent queueing networkM/G/c/c models and the individual workstations are modeled with exponentially distributed single and multi-server M/M/c queueing models. The coupling of these queueing models is unique via the material handling structure. The performance modeling of the systems for series, merge, and split and other complex network topologies are included so as to demonstrate the type of topological network design that is possible with these incorporated material handling systems. Of some importance, it is shown that these integrated M/M/c and M/G/c/c networks have a product form when the population arriving at the M/G/c/c queues is controlled. Numerous experimental results demonstrate the efficacy of our approach for a variety of contexts and situations

The impact of behavioural factors in the renewable energy investment decision making process: Conceptual framework and empirical findings

A. MASINI, E. Menichetti

Energy Policy

janvier 2012, vol. 40, n°1, pp.28-38

Départements : Information Systems and Operations Management, GREGHEC (CNRS)

Mots clés : Adaptive conjoint analysis, Behavioral finance, Investments, Renewable energy policy, Multivariate regression

Investments in renewable energy (RE) technologies are regarded with increasing interest as an effective means to stimulate growth and accelerate the recovery from the recent financial crisis. Yet, despite their appeal, and the numerous policies implemented to promote these technologies, the diffusion of RE projects remains somehow below expectations. This limited penetration is also due to a lack of appropriate financing and to a certain reluctance to invest in these technologies. In order to shed light on this phenomenon, in this paper we examine the decision making process underlying investments in RE technologies. We propose and test a conceptual model that examines the structural and behavioral factors affecting the investors decisions as well as the relationship between RE investments and portfolio performance. Applying econometric techniques on primary data collected from a sample of European investors, we study how the investors a-priori beliefs, their preferences over policy instruments and their attitude toward technological risk affect the likelihood of investing in RE projects. We also demonstrate that portfolio performance increases with an increase of the RE share in the portfolio. Implications for scholars, investors, technology managers and policy makers are derived and discussed

The Offline Executive


Strategy and Business

hiver 2012, vol. 69

Départements : Information Systems and Operations Management, GREGHEC (CNRS)

A manager’s effectiveness depends not only on using e-mail and other electronic communication, but also on learning to shut it down