Optimizing preventive maintenance over a finite planning horizon in a semi-Markov framework

2020 ◽  
Author(s):  
Antonio Sánchez Herguedas ◽  
Adolfo Crespo Márquez ◽  
Francisco Rodrigo Muñoz
Keyword(s):  
Preventive Maintenance ◽  
Recurrence Relations ◽  
Direct Calculation ◽  
Planning Horizon ◽  
Practical Implementation ◽  
Practical Application ◽  
Mathematical Solution ◽  
Accumulated Reward ◽  
Finite Planning Horizon

Abstract This paper describes the optimization of preventive maintenance (PM) over a finite planning horizon in a semi-Markov framework. In this framework, the asset may be operating, and providing income for the asset owner, or not operating and undergoing PM, or not operating and undergoing corrective maintenance following failure. PM is triggered when the asset has been operating for τ time units. A number m of transitions specifies the finite horizon. This system is described with a set of recurrence relations, and their z-transform is used to determine the value of τ that maximizes the average accumulated reward over the horizon. We study under what conditions a solution can be found, and for those specific cases the solution τ* is calculated. Despite the complexity of the mathematical solution, the result obtained allows the analyst to provide a quick and easy-to-use tool for practical application in many real-world cases. To demonstrate this, the method has been implemented for a case study, and its accuracy and practical implementation were tested using Monte Carlo simulation and direct calculation.

CARVER+Shock method and its application in a catering company in Poland

2017 ◽  
Vol 119 (12) ◽  
pp. 2610-2629
Author(s):  
Małgorzata Wiśniewska
Keyword(s):  
Research Method ◽  
Design Methodology ◽  
Scientific Literature ◽  
Practical Implementation ◽  
Practical Application ◽  
Final Phase ◽  
Content Type ◽  
First Case ◽  
The Subject

Purpose The purpose of this paper is to present the practical implementation of the CARVER+Shock (CS) method and describe the following steps of vulnerability assessment on the basis of a catering company, and to confirm that it can be successfully applied by the restaurant for better preparation regarding potential, intentional contamination. Design/methodology/approach The research method is a case study, including examining the company’s documentation and the interview with the company owner. The analysis refers to the following seven attributes: criticality, accessibility, recuperability, vulnerability, effect, recognizability and shock. Findings The practical application of CS method in company allows indicating the most vulnerable phases of the catering process. The values of “recuperability,” “effect” and “shock” are increasing along with the development of the catering process. The lowest risk of threat is observed at the first phases of the catering process, and the most risky were those connected with the preliminary consumption phase and with the final phase, which is arranged in the place of the event. The attributes “recognizability” and “effect” have the greatest influence on the outcome. The closer the food gets to the consumer, the higher is the risk of intentional contamination, and the harder it is to reverse its effects. Originality/value In the scientific literature, there is a gap observed in the subject of applying the CS method. This is the first case study presentation referring to its application in catering processes in Poland.

Optimising the Preventive Maintenance Interval Using a Semi-Markov Process, Z-Transform, and Finite Planning Horizon

2022 ◽  
pp. 137-161
Author(s):  
Antonio Sánchez-Herguedas ◽  
Adolfo Crespo-Márquez ◽  
Francisco Rodrigo-Muñoz
Keyword(s):  
Markov Process ◽  
Preventive Maintenance ◽  
Decision Support Tool ◽  
Planning Horizon ◽  
Good Decision ◽  
Support Tool ◽  
Semi Markov Process ◽  
Maintenance Policies ◽  
Time Planning ◽  
Finite Planning Horizon

This chapter uses a semi-Markov process and the z transform to find the optimal preventive maintenance interval when dealing with maintenance decision making for a finite time planning horizon. The result is a method that can be easily implemented to assets for which a Weibull reliability analysis exists. The suggested preventive interval formulation is simple and practical. The requirements to apply this simple formula are related to the existence of asset´s reliability data as well as cost/rewards that the assets have when remaining or transitioning to a given state. The application of this method can be very straightforward, and the tool can become a good decision support tool allowing “what if” analysis for different time horizon and maintenance policies.

scholarly journals The Case Study of Bottlenecks Identification for Practical Implementation to the Theory of Constraints

2018 ◽  
Vol 1 (1) ◽  
pp. 399-405
Author(s):  
Wieslaw Urban ◽  
Patrycja Rogowska
Keyword(s):  
Production System ◽  
Theory Of Constraints ◽  
Practical Implementation ◽  
Practical Application ◽  
Homogeneous Flow ◽  
Comprehensive Plan

Abstract According to the Theory of Constraints by Goldratt system bottlenecks are key to improving productivity and profitability of the entire production system. An important issue in the practical application of this theory is to identify bottlenecks in the system. The aim of this paper is to develop practical steps to identify bottlenecks in the production system characterised by a homogeneous flow. The paper includes a case study which shows six steps that allowing to specify not only the first bottleneck of the system but to develop a comprehensive plan for removing bottlenecks.

scholarly journals e-Navigating in highly-constrained waters: a case study of the Vistula Lagoon

2021 ◽  
pp. 1-10
Author(s):  
Adam Weintrit ◽  
Jacek Pietraszkiewicz ◽  
Wiesław Piotrzkowski ◽  
Wojciech Tycholiz
Keyword(s):  
High Resolution ◽  
Global Solution ◽  
Transition Process ◽  
Practical Implementation ◽  
Vistula Lagoon ◽  
Digital Era ◽  
High Resolution Bathymetry ◽  
Marine Navigation ◽  
The Vistula Lagoon

Abstract In recent years the transition of marine navigation to the digital era has been gaining momentum. Implementation of e-Navigation solutions varies from country to country in terms of their priorities, goals, levels and effects. Maritime authorities in Poland have been setting the pace in this transition process, not only in Poland but also in general as a global solution. The most recent example is the planned deployment of a variety of e-Navigation tools in the Vistula Lagoon: from GNSS-RTK Ground-Based Augmentation System, to virtual and synthetic aids to navigation, high-resolution bathymetry and advanced navigational software for piloting. The major objectives of this paper are, first, to summarise recent dynamics in the e-Navigation field, and second, to present a practical implementation of the e-Navigation concept in the Vistula Lagoon area.

scholarly journals R–R–T (resistance–resilience–transformation) typology reveals differential conservation approaches across ecosystems and time

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Guillaume Peterson St-Laurent ◽  
Lauren E. Oakes ◽  
Molly Cross ◽  
Shannon Hagerman
Keyword(s):  
Climate Change ◽  
Empirical Evidence ◽  
Climate Change Adaptation ◽  
Conservation Practices ◽  
Practical Application ◽  
Empirical Assessment ◽  
Transformative Action ◽  
Conservation Actions

AbstractConservation practices during the first decade of the millennium predominantly focused on resisting changes and maintaining historical or current conditions, but ever-increasing impacts from climate change have highlighted the need for transformative action. However, little empirical evidence exists on what kinds of conservation actions aimed specifically at climate change adaptation are being implemented in practice, let alone how transformative these actions are. In response, we propose and trial a novel typology—the R–R–T scale, which improves on existing concepts of Resistance, Resilience, and Transformation—that enables the practical application of contested terms and the empirical assessment of whether and to what extent a shift toward transformative action is occurring. When applying the R–R–T scale to a case study of 104 adaptation projects funded since 2011, we find a trend towards transformation that varies across ecosystems. Our results reveal that perceptions about the acceptance of novel interventions in principle are beginning to be expressed in practice.

scholarly journals Applying the PECSL: using case studies to demonstrate the Pedagogy of Experience Complexity for Smart Learning

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Pen Lister
Keyword(s):  
Real World ◽  
Mobile Apps ◽  
Urban Environments ◽  
Learning Activities ◽  
Learning Activity ◽  
Opportunities To Learn ◽  
Practical Application ◽  
Design And Development ◽  
Smart Learning

AbstractThis paper discusses the uses and applications of the Pedagogy of Experience Complexity for Smart Learning (PECSL), a four-tier model of considerations for the design and development of smart learning activities. Using existing mobile apps and relevant activities as illustrative examples, the PECSL is applied to indicate concepts and mechanisms by which useful pedagogical considerations can work alongside user-centred design principles for the design and development of smart learning in urban hyper-localities. Practical application of the model is discussed using real world examples of activities as a basis to demonstrate the potential for manifold opportunities to learn, and plan for experience complexity in a smart learning activity. Case study approaches reflect on aspects of the PECSL in how it might be a useful and pragmatic guide to some of the issues faced when designing digital citizen learning activities in complex urban environments.

Assets-based approaches to developing age friendly communities: learning from the bristol ageing better programme

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Amy Beardmore ◽  
Penny Beynon ◽  
Christine Crabbe ◽  
Carol Fry ◽  
Jan Fullforth ◽  
...  
Keyword(s):  
Community Development ◽  
Older People ◽  
Production Method ◽  
Project Delivery ◽  
Development Projects ◽  
Practical Application ◽  
Content Type ◽  
Diverse Groups ◽  
Practical Implications

Purpose International attention is increasingly turning to the challenge of creating age-friendly environments. This study aims to examine the application of asset-based approaches in undertaking community development projects with older people. The paper intends to share the learning that may be useful when designing community development projects for older people in the future. Design/methodology/approach This study followed a multiple project case study design, with a focus on project delivery practices. It was undertaken as a co-production exercise involving university researchers and trained older volunteer community researchers (CRs). Over 18–24 months of qualitative research was conducted in relation to six area-based urban projects between 2018 and 2020. Findings There were five leading themes as follows: mapping and building on assets in highly localised settings; creating governance and direction through steering groups; developing activities with diverse groups of older people; reaching isolated and lonely older people; building local capacity to embed sustainability. Practical implications The effectiveness of assets-based approaches in promoting age-friendly agendas appears to be contingent on the values, skills, capacity and resourcing of delivery agencies, alongside wider public sector investment in communities. Diversity and inequalities amongst older people need to be taken into account and community development that specifically focuses on older people needs to be balanced with the whole population and intergenerational practice. Originality/value This paper provides an empirical account of the practical application of assets practices specifically in the context of the age-friendly community agenda. The co-production method brings together insights from academic and volunteer older CRs.

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