Search results for "Operations"

Caring for older people: an analysis of the small business sector

2012

This study aims to analyse the small business sector in Spain for institutional care. In the Autonomous Region of Valencia, this sector is represented by non‐profit institutions. Our results show that non‐profit centres easily fulfil the legal requirements, especially with regard to personnel. They are generally of high quality and receive a large amount of volunteer work and funds from donators. Small business centres show an accurate daily cost per user of up to €56.48, a substantially lower rate than those offered by large centres.

A Multi-Objective Design Approach for the c Chart Considering Taguchi Loss Function

2013

The present paper proposes a multi-objective design approach for the c chart, considering in the optimization process of the chart parameters both the statistical and the economic objectives. In particular, the minimization of the hourly total quality related costs is the considered objective to carry out the economic goal, whereas the statistical objective is reached by the minimization the out-of-control average run length of the chart. A mixed integer non-linear constrained mathematical model is formulated to solve the treated multi-objective optimization problem, whereas the Pareto optimal frontier is described by the e-constraint method. In order to show the employment of the proposed …

Comparing the Economic Effectiveness of Various Adaptive Schemes for the c Chart

2013

In an attempt to improve the effectiveness of statistical process control (SPC) procedures, a variety of adaptive schemes has been developed in the last decades. However, considering control charts for attributes, relatively few works about adaptive schemes have been proposed, and most of them were proposed only recently. The common characteristic of those schemes is that one or more chart parameters are allowed to adaptively vary during the SPC operations according to the sampling information history, typically the current point plotted on the chart. In this way, the adaptive schemes are smarter than the related static ones, but they are also more complicated in terms of implementation. Th…

An Effective Double Sampling Scheme for thecControl Chart

2013

In the present paper is developed a statistical process control inspection procedure based on a new simple-to-implement and effective double sampling scheme for the c control chart, aimed at the minimization of the number of inspected observation units and warranting fixed levels for the type I and II error risks. In particular, the formulations of the false alarm risk α, the power P of the chart, and the expected number of inspected observation units for the developed inspection procedure are given, whereas a macro of Microsoft Excel is adopted to solve the tackled problem. In order to illustrate the application of the developed approach and to investigate on the influence of several opera…

Economic Design Approach for an SPC Inspection Procedure Implementing The Adaptive C Chart

2013

The present paper proposes a design approach for a statistical process control (SPC) procedure implementing a c control chart for non-conformities, with the aim to minimize the hourly total quality-related costs. The latter take into account the costs arising from the non-conforming products while the process is in-control and out-of-control, for false alarms, for assignable cause locations and system repairs, for sampling and inspection activities and for the system downtime. The proposed economic optimization approach is constrained by the expected hourly false alarms frequency, as well as the available labor resource level. A mixed integer non-linear constrained mathematical model is dev…

Strategies for Exploring Functions from Dynamic Combinatorial Libraries

2020

Co-produzione di valore nei servizi museali e performance multidimensionali: un approccio dinamico a supporto del management culturale

2021

Contesto della ricerca: nei piccoli centri urbani la co-produzione di servizi museali può essere una leva per la generazione di valore pubblico. Obiettivi del paper: lo scritto mira ad illustrare come un approccio multidimensionale di performance governance sia in grado di offrire una prospettiva sistemica per l’identificazione degli outcome gestionali, organizzativi e di comunità nonché di evidenziare leve per il miglioramento dei processi di generazione di valore nei musei e a beneficio della comunità. Metodologia: dapprima si è proceduto alla revisione della letteratura sul tema della co-produzione di servizi pubblici. Per analizzare le performance di tali contesti collaborativi si è cos…

The on-demand warehousing problem

2022

Warehouses are key elements of supply chain networks, and great attention is paid to increase their efficiency. Highly volatile space requirements are enablers of innovative resource sharing concepts, where warehouse capacities are traded on online platforms. In this context, our paper introduces the on-demand warehousing problem from the perspective of platform providers. The objective prioritises demand–supply matching with maximisation of the number of transactions. If there is a tie, the secondary objective maximises the number of suppliers matched with at least one customer and the number of customers that have matches within a specific threshold with respect to the minimum achievable …

A beam search algorithm for minimizing crane times in premarshalling problems

2022

The premarshalling problem consists of sorting the containers placed in a bay of the container yard so that they can be retrieved in the order in which they will be required. We study the premarshalling problem with crane time minimization objective and develop a beam search algorithm, with some new elements adapted to the characteristics of the problem, to solve it. We propose various evaluation criteria, depending on the type of container movement, for its local evaluation; a new heuristic algorithm including local search for blue its global evaluation; and several new dominance rules. The computational study shows the contribution of each new element. The performance of the complete algo…

Use of Battery- vs. Petrol-Powered Chainsaws in Forestry: Comparing Performances on Cutting Time

2022

The use of battery tools is very common in many fields of work. In fact, the electric engine and batteries have several advantages over traditional endothermic engines, including low emissions, in terms of pollutants, vibration and noise. In this context, the chainsaw market started producing electric models powered by batteries. These machines can be useful in forestry, but information on their performance is scarce. The aim of this work was to compare the performance, in terms of cutting times, of three Stihl chainsaw models: the MS 220C-B (battery powered), and the MS 201 C-M and MS 261 C-M (both petrol powered). The study was carried out on five different wood species, also taking into …