This special issue presents a selection of papers from the International Conference on Industrial Engineering and Systems Management (IESM'05) held in Marrakech, Morocco on 16–19 May 2005. The selection process has been carried out in two phases: a first review by two anonymous referees based on a short version of the papers (about 10 pages) that were included in the IESM proceedings and a second review by two other referees based on the complete version of the papers. This explains the time interval between the date of the conference and the publication date of this issue.
Twelve papers have been selected that present advances and new results concerning the design and performance evaluation of manufacturing systems and production lines as well as supply chains.
First, the paper entitled Aiding Design with Constraints: an Extension of Quad Trees in order to deal with Piecewise Functions by Aldanondo et al. deals with preliminary design considered as a constraint satisfaction problem (CSP). The proposed approach permits the handling of constraints, given as graphs or charts, in a CSP. This kind of problem is frequently encountered in engineering, especially when knowledge comes from experience. The paper shows that the quad trees techniques can be extended when a constraint is defined by a piecewise function or by a set of numerical functions defined on intervals.
Next, Feyzioğlu and Büyüközkan, in An integrated group decision-making approach for new product development, extend the quality function deployment (QFD) methodology by introducing a new group decision-making approach that takes into account multiple preference formats and fusing different expressions into one uniform group decision by means of fuzzy set theory. They also propose a benchmarking procedure based on the Choquet integral to rate competing systems and to find which dimensions should need improvement.
The paper by Finel et al., A random search and backtracking procedure for transfer line balancing, consists of finding the best partition in terms of blocks and workstations in the set of all operations to be executed on the line. An optimal decision must satisfy a desired productivity rate as well as precedence and compatibility constraints for machining operations. The proposed approach deals with mathematical modelling of the considered problem and with the search of a good and, if possible, optimal solution of this model, minimizing the amount of equipment used and consequently the line cost.
Kacem and Chu, in Minimizing the weighted flowtime on a single machine with resumable availability contraint: Worst-case of the WSPT heuristic, consider the scheduling problem on a single machine with one planned unavailability period in the resumable case. They assume that if a job cannot finish before the maintenance period, then it can be resumed after the end of maintenance (resumable case). They study the minimization of the weighted sum of the completion times. Then, they analyse the properties of the preemptive WSPT heuristic. Finally, they show that the problem has a worst-case bound equal to two under some conditions.
Savsar, in his paper Modelling of multi-stage production lines with maintenance operations, presents a discrete mathematical model integrated into an iterative simulation procedure to determine the production output rate of a multi-stage line with corrective and preventive maintenance operations. This type of analysis may be required once at the design stage of a line to determine buffer capacities and at the operation stage to determine effects of various maintenance policies for best policy selection.
In the paper entitled Development of Simulation and Optimization Platform to Analyze Maintenance Policies Performances for Manufacturing Systems, Roux et al. propose a new approach integrating optimization algorithms and simulation methods to analyse maintenance strategies performances for manufacturing systems in which operating characteristics deteriorate with use and whose lifetime and repair duration are random. The simulation language RAO (resource–action–operation) is used to implement the proposed approach. Numerical examples are carried out to validate the approach flexibility and efficiency.
In Efficacy and efficiency indexes for a multi-criteria industrial performance synthesized by Choquet integral aggregation, Berrah et al. describe how the Choquet integral aggregation operators can address the problem of taking interactions between performance criteria into account. They propose an inefficacy index that quantifies the contribution of one elementary performance to the overall performance inefficacy, and an efficacy index that quantifies the relevance of one elementary performance increase versus the minimal performance increase required to reach the overall one. This approach has been applied to a real industrial problem.
Nowadays, intense competition forces enterprises to pay more attention to supply chain collaboration with their upstream and downstream partners. Derrouiche et al. in Supply Chain Management: A framework to characterize the Collaborative Strategies propose a framework, based on analysis grids and graphical representations, which helps for better characterizing of different collaborative strategies such as quick response, efficient consumer response, vendor managed inventory or collaborative planning, or forecasting and replenishment (CPFR). The analysis grids use several characterization criteria to express the collaboration nature and its extent. For a better understanding, this framework is then applied to the CPFR strategy.
The paper by Bertel et al., Optimal cash flow and operational planning in company supply chain, presents a global solution to integrate financial and physical flow in the operational planning. The supply chain is modelled as a flow shop in which financial metrics are integrated. A mixed integer linear program is proposed and applied to a case study in order to optimize the supply chain operation. A heuristic (a greedy algorithm) is suggested. Lower and upper bounds for the problem are proposed.
The paper by Pirard et al., A generic scalable simulation model for strategic supply chain management with emphasis on production activities, presents a simulation model for strategic supply chain management of multi-site enterprises. Particular attention has been paid to the modelling of the production activities in the production centres, since it has been established that these activities strongly influence the replenishment lead time. The results analysis shows that the inventory management policies at the distribution centres have an influence on the financial performances and on the level of service offered to the final customers. These two metrics are also influenced by the production orders assignment policy at the production centres.
In Competency and preference based personnel scheduling in large assembly lines, Sabar et al. introduce a formal description and mathematical modelling of the personnel scheduling problem in the context of a paced multi-product assembly centre, explicitly taking into consideration the individual competencies and preferences of each worker, as well as the personnel and competency requirements associated with each assembly activity given both the current master assembly schedule and line balancing for each product.
The final paper puts forward that the great difficulty related to traffic management of the urban collective transport network is in respect of the vehicle planned departure and arrival times at/from the different stops in the traffic network. Ould Sidi et al., in their paper entitled A novel approach to developing and evaluating regulation strategies for urban transport disrupted networks, present a decision support system for urban transport networks' regulation and evaluation. A mathematical formulation of the transport regulation problem is given and two new criteria for decision evaluation are introduced. The proposed evaluation method uses a hybrid approach based on evolutionary algorithms, fuzzy logic and Choquet integral.
The Guest Editors would like to warmly thank the authors and the reviewers for their contribution to this special issue. Ms. Anne-Lise Pieders, IESM secretary, deserves special recognition for her valuable administrative work.