Search

The paper overviews different auction-based mechanisms applicable in market-like models for solving job-shop scheduling problems. In addition, a particular insight is provided on the adoption of an English-based auction. The most meaningful algorithms used within the bidding process between resource agents and part agents are widely described and their behaviour analysed. Preliminary experimental results are reported and discussed.

In the last few years, changes in the manufacturing environment have increasingly driven enterprises towards the research of new ways to manage and reorganise their production systems. In particular, as regards operations management and control, research is progressively shifting from hierarchical to heterarchical architectures which are founded on distributed decision-making entities interacting through particular cooperative mechanisms.

Since the mid-1980s, when we recognized that the traditional financially-oriented performance measurement systems no longer met the requirements of modern enterprises, we have seen a significant growth in research and development efforts concerning performance measurement by academics, consultants and practitioners, resulting in the emergence of various frameworks, tools and techniques for performance measurement.

This work presents the effect, in terms of travel distance and material handling time reductions, of an optimal rather than a uniform item allocation in one-block picking warehouses, both with and without the use of a simple picking heuristic. Since developing efficient product-location strategies represents a critical issue in Operations Management, due to the impact on warehouse performance in terms of both service level and operation costs, this paper focuses on an effective quantification of obtainable travel time reductions, obtaining a significant result for manufacturing companies aiming to determine the most appropriate material handling resource configuration. Building on previous work on the effect of slot-code optimization on travel times in single/dual command cycles, the authors broaden the scope to include the most general picking case, thus widening the range of applicability and realising former suggestions for future research.

Information sharing among supply chain echelons is now an acquired result. As a consequence, most of the traditional techniques and procedures in production management must be revised and updated, exploiting the opportunities provided by new technologies. This paper presents an improved version of Material Requirement Planning procedure, which assumes information sharing capabilities and permits the creation of new business opportunities. In Orlicky's MRP, orders are computed considering the parent items gross requirements. On the contrary, here the order release procedure related to a certain item is computed both by exploiting all the information sharing advantages and by introducing a drastic innovation to the main process functioning. As a result, the proposed algorithm copes better with demand uncertainty, lowers the system nervousness and also removes the need for continuous forecast adjustments, thereby improving the ease in managing the material flow, allowing the development of new forms of collaboration among different supply chain partners and the creation of new business networks. The algorithm is presented in formulas to describe in detail each procedure step and calculations.

Each productive system manager knows that finding the optimal trade-off between reducing inventory and decreasing the frequency of production/replenishment orders allows a great cut-back in operations costs. Several authors have focused their contributions, trying to demonstrate that among the various dynamic lot sizing rules there are big differences in terms of performance, and that these differences are not negligible. In this work, eight of the best known lot sizing algorithms have been described with a unique modelling approach and have then been exhaustively tested on several different scenarios, benchmarking versus Wagner and Whitin's optimal solution. As distinct from the contributions in the literature, the operational behaviour has been evaluated in order to determine which one is more suitable to the characteristics of each scenario.

As a means of avoiding stock-outs, safety stocks play an important role in achieving customer satisfaction and retention. However, traditional safety stock theory is based on the assumption of the immediate delivery of the ordered products, which is not a common condition in business-to-business contexts. Virtual safety stock theory was conceived to raise the service level by exploiting the potential time interval in the order-to-delivery process. Nevertheless, its mathematical complexity prevented this technique from being widely adopted in the industrial world. In this paper, we present a simple method to test virtual safety stock effectiveness through simulation in an inventory system using a base stock policy with periodic reviews and backorders. This approach can be useful for researchers as well as practitioners who want to model the behaviour of an inventory system under uncertain conditions and verify the opportunity for setting up a virtual safety stock on top of, or instead of, the traditional physical safety stock.

Several authors have emphasized the importance of analysing the impact of e-business, e-commerce and online-shopping on supply chain and operations management; however, it seems that to date no one has suggested a comprehensive framework that could help identify and support supply chain design decisions for companies about to enter the online-business in the consumer goods retail trade, encompassing the business drivers at a strategic level. This paper aims to bridge the gap between theoretical taxonomies or abstract models and the concrete supply chain design problems encountered by logistics managers who need to take their Food & Beverage retail company into the internet business while also preserving a consistent alignment with their current company strategy. Some insights on this area are presented along with a field study approach and a proposal of a 6-phase framework to jointly manage all the relevant strategic and functional aspects of supply networks.

Given the increasingly significant impact of an efficient product-location strategy on warehouses' performance from a service level and operational costs perspective, this paper presents a possible operations research-oriented solution to provide a tangible reduction of the overall required warehousing space, thereby translating the storage location assignment problem (SLAP) into a vertex colouring problem (VCP). Developing the topic of their previous work on the development of an effective multi-product slot-code optimization heuristic, the authors focused on finding a cost-effective way to solve the SLAP through a mathematical-optimization approach. The formulation validation on a real industrial case showed its high optimization potential, and benchmarking simulations displayed performances significantly close to the best theoretical case. Indeed, the optimized value results were definitively close to the SLAP lower bound calculated assuming a randomized storage policy which, distinct from the developed solution, must inevitably be supported by warehouse management system software. On the contrary, the proposed methodology relies upon a dedicated storage policy, which is easily implementable by companies of all sizes without the need for investing in expensive IT tools.

Service Engineering (SE) discipline is currently supporting companies during the engineering and re-engineering phases of their service offering. With the support of SE methods, companies can undertake their servitization journey with the best premise to gain as well as deliver value to their customers. For this purpose, the Service Engineering Methodology (SEEM) has been proposed. The SEEM entails methods to design service concepts and processes capable of balancing value between customers and the company. Some industrial cases, carried out in collaboration with ABB, a leading provider in power and automation technology, demonstrate the effectiveness of such methodology in the re-engineering of existing services in B2B context. Despite that, the cases show that the SEEM application is time consuming, especially in the validation of the service provision process. Thus, in order to facilitate and speed up the implementation of the methodology, a standard process for service provision becomes relevant. Then, starting from the re-engineering of the existing product-oriented services offered by ABB, this paper aims at laying the foundation for the definition of a reference model and a standard process model for product-oriented service delivery. The results will support the SEEM adoption and the definition of service processes avoiding the design of customized models, that cannot be compared and adapted to different realities. In line with what has been found in literature, the definition of a possible reference model and a preliminary standard process model are presented.

Modern companies face immense market pressure to meet customers’ demands while ensuring the sustainability of business. Consumers are now requesting highly customized products and services, i.e. demanding mass customization from manufacturing companies. The complete value chain needs to develop strategies enabling interaction with customers and consumers, supporting customization of features and services, and even co-design. This paper presents the DIVERSITY approach, which consists on a methodology and engineering environment supporting companies in using social media to realize a context sensitive lean design process of product service systems.

In recent years, the economic and financial crises have been slowing down the growth of international markets. The resulting necessity to increase competitiveness has forced manufacturing industries to rethink their offer portfolio, also implementing servitization strategies. In particular, given the dramatic raise of customers’ awareness as regards environmental and energy problems, the energy industry is also considering the provision of Product-Service System (PSS) solutions (i.e. the bundle of energy services to energy efficiency related products) as a profitable alternative. However, the design of PSS and in particular of the service content of the offer is a challenging activity, mainly due to the fact that services are by definition characterized by high level of intangibility and perishability, and to the fact that standard tools and methodologies for service engineering are not available. The SErvice Engineering Methodology (SEEM) [1] aims at supporting companies in these design and implementation phases. The methodology is in its development phase and its applicability in industry has been mainly tested in one specific context. This paper deals with the application of SEEM in the context of Energy Services (ESs) where the design phase can be much more complex than in other areas due to the variety of industries offering this kind of services and to the number of stakeholders involved during the service provision. In particular, this paper refers to a specific ES (the provision of data elaboration and analysis to energy consumption monitoring and control purposes) marketed together with energy meters. The general aim of this work is to provide a first analysis and a general understanding of the applicability of this existing methodology to the ES field by the mean of a real case study. In the paper, main steps of the application of the SEEM to the case study are described and discussed, to highlight main criticalities. In the end, a critical analysis is provided in order to put the basis to generalize the insights of this work to additional Energy Services.

As for conventional products, the profit generation and the market success of Product Service Systems (PSS) critically depend on the decisions taken during the initial lifecycle stages, when PSSs are conceptualized, designed, developed and engineered. Successful cases show the adoption of lean techniques in the early stages of products development, impelling the authors to assess the application of the same approaches also to PSS development. For this reasons the paper aims to report the state of the art of PSS Design research, relating this strategic process to the Lean Thinking approaches typically applied in traditional Product Development and Manufacturing. The literature about PSS is classified and Lean Thinking evolvement from product manufacturing to design phases is described. On this basis, the paper defines which are the aspects of Lean Thinking already applied in PSS Development also uncovering gaps and lacks of the methods proposed by the scientific literature so far. This opens the way to new opportunities and challenges through many further research and industrial projects.

In this paper the economical feasibility of a system based on the membrane filtration process for the phenolic compound extraction and the subsequent polyphenolic enrichment of the olive oil, have been assessed. In particular, the analysis of the investment profitability of a case study was presented to determine the optimal incremental price of the olive oil obtained by the enrichment process

This paper deals with the problem of the maintenance scheduling in a multi-component system for which a required reliability level has to be warranted until the next planned stop for maintenance. Particularly, the tackled problem concerns both the determination of the elements set on which to perform preventive maintenance and the optimal number of maintenance crews in order to warranty the required reliability level at the minimum maintenance cost. The problem is formulated as a mathematical programming model that becomes very hard to solve for large practical systems. For such reason, a new effective approach based on a constrained genetic algorithm is herein proposed and tested with reference to a naval diesel propulsion unit.

International audience; Far from being a mere production-oriented mission, competition among companies has to be considered as a much wider concept, largely based on effective supply chain management. Implementing suitable supply chain strategies is indeed crucial for enterprises seeking to strengthen their own position in the market against their competitors. With this recognition, one of the main issue in the logistic field is the suppliers and orders management, that is a complex decision-making problem depending on a wide set of aspects mutually correlated and often conflicting each other. This is the reason why assuming a Multi-Criteria Decision-Making (MCDM) perspective is useful to deal with the topic of interest. In particular, the present paper is aimed at sorting out a real world case study about distributing and dispatching orders, through a MCDM approach based on the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). On the one hand, this method is proposed to prioritise the vehicles used to transfer orders, by taking into account criteria such as pallet capacity, tailgate presence, energy type and so on. On the other hand, a final ranking of orders to be delivered will be achieved under the evaluation of aspects such as loading/unloading time, kind of vehicle and driver, among others. Final results will be helpful to establish a degree of priority in assigning orders to vehicles and their robustness will be checked by performing a sensitivity analysis on criteria weights.

PSS development involves together, through the servitization phenomenon, both manufacturing and service workers carrying great potential to pursue industrial competitiveness, customer satisfaction and sustainable improvement. The belief is that the development level of PSS design is slowly evolving through a path strongly driven by the evolution of the technology and the progressive involvement of the industry in its application. However companies still need best practices able to improve the PSS development processes performances in a more systematic way. Lean techniques already managed to provide these procedures in a product context allowing the improvement of both product manufacturing and product development processes. The evolution of Lean to an intangible dimension also guided companies’ convergence strategy from mass production to mass customization in an efficient and effective way. For this reasons the paper aims to investigate the literature about Lean Thinking evolvement from manufacturing to design phases, as well as from product to service. On this basis, the definition of which are Lean Thinking aspects which could positively affect also PSSs Development will enable the authors to understand which are the more suitable tools to develop Lean PSS and how to provide companies best practices able to improve the PSS development processes performances in a more systematic way. This opens the way to new opportunities and challenges through many further research and industrial projects.

Maintenance plays an important role in achieving the organizational goals so that the measurement of its effectiveness and efficiency has become an essential element of industrial strategy. In literature several Maintenance Key Performance Indicators (MKPIs) are proposed but none structured approach is suggested to select the best set of MKPIs able to synthetically describe a specific maintenance context. The paper proposes a structured methodology for the maintenance performance measurement by means of MKPIs. Firstly, a multi-level hierarchical framework able to synthesize the most meaningful perspectives affecting the performance of the maintenance process is designed. Successively, some MKPIs proposed in the literature are assigned to the hierarchical framework and ranked by an Analytic Hierarchy Process-based approach. A procedure to deal with incomplete and inconsistent pair-wise comparison matrices is proposed. Finally, a mathematical model is formulated to select the set of MKPIs representing the best compromise between the completeness and the conciseness of the returned information