Sustainable choice of the location of a biomass plant: an application in Tuscany

The management of complex systems often requires taking decisions that may affect the company's future. Making decisions is not easy and requires you to take serious responsibility. The company character appointed to this task, is the “decision-makers” who, within a job or project, must make a selection among several alternatives. To carry out this task, you must perform a process called "decision analysis". It can be aided by qualitative and quantitative tools, able to rationalize a multifactorial choice and bring it to a judgment of performance parameters more easily comparable. In fact, if this problem is addressed considering only the economic aspects, other fundamental parameters will be neglected such as, for example, the environmental ones. Actually, bringing many different aspects to a simple economic performance, or anyway one-dimensional, proves to be a limiting and unsatisfactory approach. In addition, if we consider the concepts of sustainability, we should at least take into account the three dimensions that describe it, namely the economic, environmental and social issues. Then, a strategy of decision making more complete that could integrate all the three aspects, becomes much more appropriate. In this context, the multi-criteria analysis are particularly suitable for this purpose. In this study we aim at investigating how one of the most popular multi-criteria methods, the Analytic Network Process (ANP) can be used to define the location of a cogeneration plant fuelled by biomass. The novelty of this study consists of having categorized and divided into homogeneous areas an entire region. In addition, to evaluate the economic efficiency, as compared to other authoritative work on the subject, also the water content in the raw material was considered, influencing the amount of biomass consumed. The results show that the ANP allows decisions making according to an overall view, considering a wide variety of parameters and allows the decision makers to better represent the needs of the stakeholder

Design of critical infrastructures: application to electrical systems

The recent publication of the 5th revision of TIA 942 standard represents a benchmark framework to design resilient power systems. This standard provides a classification for electric infrastructures in terms of their capacity to tolerate failures and to allow safely maintenance operations. This ranking is not based upon technical specifications, but on system resilience level, that is the capacity to resist to an unexpected destructive event, breakdown or malfunctioning which afflicts the end user. However, this standard is provided only for design purposes. Aim of this paper is to propose an approach by which the current resilience status of a system can be evaluated, in accordance to this standard classification. The proposed technique should allow to easily analyze the gap – in terms of infrastructure topology, components and distribution lines – between an existing system and a generic configuration with a desired resilience level, and thus to suggest the steps to reach the proper availability for the system specific mission. A preliminary version of the technique – which however still leaves some open issues – has been validated with the power system infrastructure that supports one of the largest datacenters in Italy, inside a primary IT Company which has to guarantee a 24/7 continuous operation of its software application, mission critical in the interests of its customers

Quality issues impacting production planning

Among the various problems affecting production processes, the unpredictability of quality factors is one of the main issues which concern manufacturing enterprises. In make-to-order or in perishable good production systems, the gap between expected and real output quality increases product cost mainly in two different ways: through the costs of extra production or reworks due to the presence of non-compliant items and through the costs originating from inefficient planning and the need of unscheduled machine changeovers. While the first are relatively easy to compute, even ex-ante, the latter are much more difficult to estimate because they depend on several planning variables such as lot size, sequencing, deliveries due dates, etc. This paper specifically addresses this problem in a make-to-order multi-product customized production system; here, the enterprise diversifies each production lot due to the fact that each order is based on the customer specific requirements and it is unique (in example, packaging or textiles and apparel industry). In these contexts, using a rule-of-thumb in overestimating the input size may cause high costs because all the excess production will generate little or no revenues on top of contributing to increasing wastes in general. On the other hand, the underestimation of the lots size is associated to the eventual need of launching a new, typically very small production order, thus a single product will bear twice the changeover costs. With little markups, it may happen that these extra costs can reduce profit to zero. Aim of this paper is to provide a critical analysis of the literature state-of-art while introducing some elements that can help the definition of lot-sizing policies considering poor quality costs

Quality issues impacting production planning

Among the various problems affecting production processes, the unpredictability of quality factors is one of the main issues which concern manufacturing enterprises. In make-to-order or in perishable good production systems, the gap between expected and real output quality increases product cost mainly in two different ways: through the costs of extra production or reworks due to the presence of non-compliant items and through the costs originating from inefficient planning and the need of unscheduled machine changeovers. While the first are relatively easy to compute, even ex-ante, the latter are much more difficult to estimate because they depend on several planning variables such as lot size, sequencing, deliveries due dates, etc. This paper specifically addresses this problem in a make-to-order multi-product customized production system; here, the enterprise diversifies each production lot due to the fact that each order is based on the customer specific requirements and it is unique (in example, packaging or textiles and apparel industry). In these contexts, using a rule-of-thumb in overestimating the input size may cause high costs because all the excess production will generate little or no revenues on top of contributing to increasing wastes in general. On the other hand, the underestimation of the lots size is associated to the eventual need of launching a new, typically very small production order, thus a single product will bear twice the changeover costs. With little markups, it may happen that these extra costs can reduce profit to zero. Aim of this paper is to provide a critical analysis of the literature state-of-art while introducing some elements that can help the definition of lot-sizing policies considering poor quality costs

Simplifying the Virtual Safety Stock formula

The paper deepen the analysis into the Virtual Safety Stock theory, which is an approach intended to drastically reduce safety inventory levels exploiting the eventual time lag between the moment when a product is ordered and the time the product needs to be available, while preserving the same performance as a production system that operates with physical safety stock. The original virtual safety stock definition embeds two major problems: a double Gaussian integral in the formulation together with the heritage of the unrealistic assumptions already included in the earliest Hadley and Whitin’s safety stock conception. This paper describes an alternative approach in which the virtual safety stock is defined with a closed-form expression much easier to compute and use in operations management practice

From business continuity to design of critical infrastructures: ensuring the proper resilience level to datacentres

Since a few years, companies that runs business critical applications are increasing their focus on their support infrastructures. Indeed, it is clearly useless to pursue higher systems reliability, when the infrastructure is vulnerable. Aim of this paper is to explore the value of business continuity within the scope of the design of resilient system. The publication of the fifth revision of ANSI/TIA/EIA 942 standard provides operation managers and risk managers with a framework to plan and design resilient infrastructures. It will be shown how to use the aforementioned standard to analyse the gap between the current and the desired resilience level of a system, and suggest the proper steps to reach it, accordingly to the business continuity requirements. This approach was adopted on the case of the power system infrastructure of a primary Italian Application Service Provider, granting 24/7 mission critical services to its customers

Storage Location Assignment Problem: implementation in a warehouse design optimization tool

This paper focuses on possible improvements of common practices of warehouse storage management taking cue from Operations Research SLAP (Storage Location Assignment Problem), thus aiming to reach an efficient and organized allocation of products to the warehouse slots. The implementation of a SLAP approach in a tool able to model multiple storage policies will be discussed, with the aim both to reduce the overall required warehouse space - to efficiently allocate produced goods - and to minimize the internal material handling times. The overcome of some of the limits of existing warehousing information management systems modules will be shown, sketching the design of a software tool able to return an organized slot-product allocation. The results of the validation of a prototype on an industrial case are presented, showing the efficiency increase of using the proposed approach with dedicated slot storage policy adoption

Storage Location Assignment Problem: implementation in a warehouse design optimization tool

This paper focuses on possible improvements of common practices of warehouse storage management taking cue from Operations Research SLAP (Storage Location Assignment Problem), thus aiming to reach an efficient and organized allocation of products to the warehouse slots. The implementation of a SLAP approach in a tool able to model multiple storage policies will be discussed, with the aim both to reduce the overall required warehouse space - to efficiently allocate produced goods - and to minimize the internal material handling times. The overcome of some of the limits of existing warehousing information management systems modules will be shown, sketching the design of a software tool able to return an organized slot-product allocation. The results of the validation of a prototype on an industrial case are presented, showing the efficiency increase of using the proposed approach with dedicated slot storage policy adoption

A rare complication of radiofrequency treatment for cellulite of the lower leg

Radiofrequency (RF) is increasingly used as an aesthetic treatment for a variety of purposes ranging from the treatment of acne scarring, cellulite correction and skin and soft tissue rejuvenation. The majority of patients experience no complications, and the treatment is therefore also frequently administered by non-medically trained staff. We present a patient, who developed severe 3rd degree burn after RF treatment requiring reconstructive surgery with a split thickness skin graft