Mónica López-Campos

A simulation model of a coordinated decentralized supply chain

This paper presents a simulation-based study of a coordinated, decentralized linear supply chain (SC) system. In the proposed model, any supply tier considers its successors as part of its inventory system and generates replenishment orders on the basis of its partners’ operational information. We show that the proposed coordinated decision-making process creates a reduction in information distortion along an SC compared with a traditional, noncoordinated strategy. A novel result is that we show how a coordinated SC can avoid the detrimental consequences of demand amplification in terms of penalty costs due to the stockout phenomenon in upstream stages.

Customer-oriented risk assessment in network utilities

For companies that distribute services such as telecommunications, water, energy, gas, etc., quality perceived by the customers has a strong impact on the fulfillment of financial goals, positively increasing the demand and negatively increasing the risk of customer churn (loss of customers). Failures by these companies may cause customer affection in a massive way, augmenting the intention to leave the company. Therefore, maintenance performance and specifically service reliability has a strong influence on financial goals. This paper proposes a methodology to evaluate the contribution of the maintenance department in economic terms based on service unreliability by network failures. The developed methodology aims to provide an analysis of failures to facilitate decision-making about maintenance (preventive/predictive and corrective) costs versus negative impacts in end customer invoicing based on the probability of losing customers. Survival analysis of recurrent failures with the General Renewal Process distribution is used for this novel purpose with the intention to be applied as a standard procedure to calculate the expected maintenance financial impact, for a given period of time. Also, geographical areas of coverage are distinguished, enabling the comparison of different technical or management alternatives. Two case studies in a telecommunications services company are presented in order to illustrate the applicability of the methodology.

Reliability Assessment Methodology for Massive Manufacturing Using Multi-Function Equipment

Experience reveals that reliability varies depending on the characteristics of operation. The manufacturing process based on multifunction equipment gives a usual case of variation in operating conditions. This work presents a methodology for the reliability analysis of multifunction processes, using the RCM approach, and a modification of the Universal Generating Function (UGF) under a massive manufacturing context. The result is a characterization of reliability, for each piece of equipment and for the production system. The methodology is applied in a workshop of a textile industry, where there is prior evidence that the failure behavior varies according to the type of function executed by multifunction machines.

Modelling and Analysis of the Apples Export Supply Chain Business Processes: Experiences from Chile

In this chapter, we present an analysis of the fresh apple export supply chain in Chile. Fresh fruits are one of the main exports in Chile, after the mining products. This supply chain is particularly complex due to its perishable nature and the fact that the fruit export season occurs during the summer period, overlapping with the arrival of cruises. For this reason, maritime ports present high levels of utilization and congestion. We follow the Business Process Analysis (BPA) methodology proposed by United Nations to model the current situation of the shipment business processes, from the warehouse or packing facility of the shipper to the port of departure where it will be loaded to the corresponding vessel. With this analysis, we identify the main challenges and opportunities and propose a redesign of the current processes. The proposed redesigned business processes consider the implementation of electronic data interchange procedures instead of the paper-based ones currently employed.

Design of Performance Indicators Based on Effective Time and Throughput Variability. Case Study in Mining Industry

The following paper proposes a method on how to analyze productive systems to achieve performance indicators that allows to know the state of the system. In particular, the objective of the paper is to analyze performance indicators that allow to understand the state of the production line in systems that present variability conditions in the performance of their equipment, and in their operational conditions that will not allow direct calculation of the effective time. It is proposed to begin with the utilization of a methodology to increase the understanding of the system, which will generate a conceptual model that will concentrate the required knowledge through a logic structure that will ease the subsequent analysis. Then, a step by step process is proposed to define the system, its performance indicators of interest, and the most efficient and effective way to obtain those, considering the existing restrictions. Finally, system and subsystem level indicators will be obtained, which will be a representation of the real state of the process, by representing the effective times, and variable throughput. All of the above will be applied in a case study in the mining industry from Chile.

A Maintenance Management Framework Based on PAS 55

This chapter shows the process of modelling a reference maintenance management framework (MMF) that represents the general requirements of the asset management specification PAS 55. The modelled MMF is expressed using the standardized and publicly available Business Process Modelling languages UML 2.1 (Unified Modelling Language) and BPMN 1.0 (Business Process Modelling Notation). The features of these notations allow to easily integrate the modelled processes into the general information system of an organization and to create a flexible structure that can be quickly and even automatically adapted to new necessities. This chapter presents a brief review about the use of UML in maintenance projects, general characteristics of PAS 55, modelling concepts and theirs applications in the project of modelling the MMF. The arguments underlying the methodology and the choice of UML and BPMN are exposed. The general architecture of the suggested MMF is described and modelled through diagrams elucidating the general operation of PAS 55. From this development is appreciated the operation structure of a software tool that can incorporate MIMOSA standards and that can be made suitable to e-maintenance functions, as an alternative from the commercial systems. Finally, some conclusions about the modelled framework are presented.

The Integration of Open Reliability, Maintenance, and Condition Monitoring Management Systems

Maintenance and assets management of an industrial plant has been always a complex activity. Nowadays, Computerized Maintenance Management Systems (CMMS) help to organize information and thus to carry out maintenance activities in a more efficient way. The emergence of new ICT has increased also the use of Condition-Based Maintenance (CBM) systems and the application of Reliability-Centered Maintenance (RCM) analysis. Each system is proved to provide benefits to the maintenance management. However, when all the systems are adopted, the lack of integration among them can prevent the maximum exploitation of their capabilities. This work aims at fulfilling this gap, proposing an e-maintenance integration platform that combines the features of the three main systems. The methodology and the reference open standards used to develop the platform are exposed. UML–BPMN diagrams represent the emerging algorithms of the designed system. The final product, a software demo, is implemented in an electric transformer.

Combined Use of Mathematical Optimization and Design of Experiments for the Maximization of Profit in a Four-Echelon Supply Chain

This paper develops a location-allocation model to optimize a four-echelon supply chain network, addressing manufacturing and distribution centers location, supplier selection and flow allocation for raw materials from suppliers to manufacturers, and finished products for end customers, while searching for system profit maximization. A fractional-factorial design of experiments is performed to analyze the effects of capacity, quality, delivery time, and interest rate on profit and system performance. The model is formulated as a mixed-integer linear programming problem and solved by using well-known commercial software. The usage of factorial experiments combined with mathematical optimization is a novel approach to address supply chain network design problems. The application of the proposed model to a case study shows that this combination of techniques yields satisfying results in terms of both its behavior and the obtained managerial insights. An ANOVA analysis is executed to quantify the effects of each factor and their interactions. In the analyzed case study, the transportation cost is the most relevant cost component, and the most relevant opportunity for profit improvement is found in the factor of quality. The proposed combination of methods can be adapted to different problems and industries.

Modelling and Simulation in Operations and Complex Supply Chains

1DICAR, University of Catania, Catania, Italy 2Industrial Management & Business Administration Department, School of Engineering, University of Seville, Seville, Spain 3Universidad de los Andes, Santiago de Chile, Chile 4Centre for Management Studies, Instituto Superior Técnico, Technical University of Lisbon, Lisbon, Portugal 5Industrial Engineering Department, Universidad Técnica Federico Santa Maŕıa, Valparaı́so, Chile 6School of Industrial Engineering, Pontificia Universidad Católica de Valparaı́so, Valparaı́so, Chile

Reliability assessment based on energy consumption as a failure rate factor

The present study defines a methodology to analyze the relationship between the failure rate of any component and the factors that can influence it, in order to link time independent operating variables to the reliability study. Characterizing the failure rate using these variables is especially useful for changing time operational contexts. To do this, a study of traditional and modern methods of analysis, together with the assumptions that must be fulfill for its implementation and the methodology for testing the assumptions is performed. Specifically, the methodology proposed in this paper is used to develop a complete study of the influence of the energy consumption of a component, at the rate of engine failure. As can be inferred, there is a relationship between energy consumption and the rate of failure; the practical experience reveals that companies frequently use the energy expenditure variable, but documented studies that corroborate their decision are not found in the literature.