Adolfo Crespo Márquez

On the concept of e-maintenance: Review and current research

The importance of the maintenance function has increased because of its role in keeping and improving system availability and safety, as well as product quality. To support this role, the development of the communication and information technologies has allowed the emergence of the concept of e-maintenance. Within the era of e-manufacturing and e-business, e-maintenance provides the opportunity for a new maintenance generation. As we will discuss later in this paper, e-maintenance integrates existing telemaintenance principles, with Web services and modern e-collaboration principles. Collaboration allows to share and exchange not only information but also knowledge and (e)-intelligence. By means of a collaborative environment, pertinent knowledge and intelligence become available and usable at the right place and time, in order to facilitate reaching the best maintenance decisions. This paper outlines the basic ideas within the e-maintenance concept and then provides an overview of the current research and challenges in this emerging field. An underlying objective is to identify the industrial/academic actors involved in the technological, organizational or management issues related to the development of e-maintenance. Today, this heterogeneous community has to be federated in order to bring up e-maintenance as a new scientific discipline.

THE EFFECTIVENESS OF USING E-COLLABORATION TOOLS IN THE SUPPLY CHAIN: AN ASSESSMENT STUDY WITH SYSTEM DYNAMICS

Abstract Developments in information technology, in recent years, have enabled major advances in electronic commerce, which is growing at a very fast pace. Although business-to-consumer (B2C) e-commerce seems to be slowing down due to economic conditions, business-to-business (B2B) e-commerce still represents the next generation of business automation. Taking advantage of new technologies, today provides an opportunity, but will be a must in the future. The use of Internet e-collaboration tools will increase in this new era. They play a role of “value creation enabler”, but at the same time they generate a wide range of new business and market “complexities” that companies have to face. This paper presents a classification of “managerial spaces” where multiple trading partners share critical information using e-collaboration tools and assesses the possible local and global impact on the supply chain (SC) performance. This is made by means of a SC model conceptualization and a simulation study with system dynamics.

Conceptual framework for e-Maintenance: Illustration by e-Maintenance technologies and platforms☆

Abstract At present we can find different complementary definitions of the term e-Maintenance. These definitions apply to maintenance several principles and concepts such as collaboration, pro-activity, knowledge, intelligence, web services or the Internet. A clear consensus is not yet reached, even when some contributions try to propose unique repositories to ensure consistency. Consequently the aim of this paper is: (a) to discuss, briefly, on the concept of e-Maintenance and on a first conceptual e-Maintenance framework based on 5 abstraction levels in order; (b) to detail the last level named “infrastructure” for illustrating e-Maintenance technologies and platforms. This level allows to put in evidence new technologies supporting e-Maintenance services and to describe e-Maintenance architecture resulting from the technologys integration. The main illustration is done with a TELeMAintenance platform (TELMA).

Operational and financial effectiveness of e-collaboration tools in supply chain integration

Abstract This paper develops a comprehensive model of supply chain integration and uses it to analyze and assess the operational and financial effectiveness of different e-collaboration tools at various levels of supply chain integration. This model is also used to evaluate the importance of the sequence in which e-collaboration tools are adopted in supply chain integration. Computational results from a validated system dynamics simulation model with different implementation sequences of e-collaboration tools and different financial scenarios show that local financial constraints can also severely impact operational and financial performance of the entire supply chain.

Models for maintenance optimization: a study for repairable systems and finite time periods

Abstract The problem of selecting a suitable maintenance policy for repairable systems and for a finite time period is presented. Since the late seventies, examples of models assessing corrective and preventive maintenance policies over an equipment life cycle exist in the literature. However, there are not too many contributions regarding real implementation of these models in the industry, considering realistic timeframes and for repairable systems. Modeling this problem requires normally the representation of different corrective and/or preventive actions that could take place at different moments, driving the equipment to different states with different hazard rates. An approach to pattern the system under finite periods of time has been the utilization of semi-Markovian probabilistic models, allowing later a maintenance policy optimization using dynamic programming. These models are very flexible to represent a given system, but they are also complex and therefore very difficult to handle when the number of the system possible states increases. This paper explores the trade-off between flexibility and complexity of these models, and presents a comparison in terms of model data requirements versus potential benefits obtained with the model.

Life Cycle Cost Analysis

The chapter presents a generic model for assets maintenance management. This model integrates other models found in the literature for built and in-use assets, and consists of sequential management building blocks. More precisely we want to show the reader the importance of selecting an appropriate method when considering the estimation of the non-reliability cost of an asset. By doing so, we show the impact of maintenance in life cycle costing and provide arguments to claim about the needs for proper assets maintenance control.

The procurement of strategic parts. Analysis of a portfolio of contracts with suppliers using a system dynamics simulation model

Abstract In this paper, we present a simulation study to extend current methods for real options strategies in the management of strategic commodity-type parts. Real options are used by procurement and financial managers to secure price and availability in the face of volatile world demand. We define, characterize and simulate three generic types of supplier contracts to accomplish varying degrees of security and flexibility. We then simulate a portfolio of these contracts applied to secure a single part, with the purpose of extending and refining portfolio valuation. We focus our attention on business dynamics based on current best practices in portfolio management, as evidenced by leaders in volatile technology businesses. The strategic part procurement system, as modeled here, includes in-transit and warehoused inventories to accommodate demand variability as well as asynchronous production and shipping lead times. In addition, the portfolio structure itself periodically creates excess inventory as negotiated terms and policies are executed in various conditions. Given these inventories and related costs, we show how optimization techniques can be used to measure the tradeoffs between alternative portfolio structures. A modified Powell method is used to carry out these optimizations properly. Finally, we describe how this more complete valuation of the portfolio is critical to option pricing models, with the ultimate potential for indexing as seen in other commodity markets.

Exploring the utilization of a CONWIP system for supply chain management. A comparison with fully integrated supply chains

Abstract Some authors have developed important advances in order to integrate and improve the performance of the supply chain (SC), by sharing information through communication technologies with a decentralized approach. An alternative to improve the performance in an SC may be to introduce a CONWIP supply chain (CONWIP SC) policy with a centralized approach in the supply chain management. In this paper we review the literature to present the benefits of the CONWIP system in different production environments and discuss the possible utilization of this system to manage the entire supply chain. A characterization of the CONWIP-based approach to supply chain management is presented, and a simulation model to explore and evaluate the advantages of this strategy, in comparison with a fully integrated supply chain (FI SC) is developed. We carry on this analysis for different levels of demand volatility and material flow constraints along the chain, and we optimize parameters to ensure the best performance of each control supply chain policy in each scenario. Our research shows that CONWIP SC policy may offer advantages and improved performances in global metrics while both policies offer similar service levels. Main advantages are smaller average of orders placed, less impact of demand variability on the ordering policy, shorter average finished goods inventory and work in process levels and potential inventory cost, substantial comparative funds savings to run the business model, and easier control of inventories.

Framework for implementation of maintenance management in distribution network service providers

Distribution network service providers (DNSP) are companies dealing with network infrastructure, such as distribution of gas, water, electricity or telecommunications, and they require the development of special maintenance management (MM) capabilities in order to satisfy the needs of their customers. In this sector, maintenance management information systems are essential to ensure control, gain knowledge and improve decision making. The aim of this paper is the study of specific characteristics of maintenance in these types of companies. We will investigate existing standards and best management practices with the scope of defining a suitable ad-hoc framework for implementation of maintenance management. The conclusion of the work supports the proposition of a framework consisting on a processes framework based on a structure of systems, integrated for continuous improvement of maintenance activities. The paper offers a very practical approach to the problem, as a result of more of 10 years of professional experience within this sector, and specially focused to network maintenance.

Maintenance policies for a production system with constrained production rate and buffer capacity

This paper considers the maintenance policies for a production system constrained by its production rate and buffer capacity to cope with unexpected failures and to deal with the variability of demand and production lead times. Using a system dynamics model, we characterize, simulate and compare results obtained by applying several maintenance policies--corrective, age-based maintenance, age and buffer-based maintenance, and modified age and buffer-based maintenance--to the system. This comparison is performed assuming that optimal values of the model parameters involved in the design of each maintenance policy have already been found by using the modified Powell method. We compare and discuss the benefits of different optimization criteria in the maintenance decision making process for a production system with constrained production rate and buffer capacity.