Risk-based maintenance of critical and complex systems

Tableau d’honneur de la Faculté des études supérieures et postdoctorales, 2016-2017.De nos jours, la plupart des systèmes dans divers secteurs critiques tels que l'aviation, le pétrole et les soins de santé sont devenus très complexes et dynamiques, et par conséquent peuvent à tout moment s'arrêter de fonctionner. Pour éviter que cela ne se reproduise et ne devienne incontrôlable ce qui engagera des pertes énormes en matière de coûts et d'indisponibilité; l'adoption de stratégies de contrôle et de maintenance s'avèrent plus que nécessaire et même vitale. Dans le génie des procédés, les stratégies optimales de maintenance pour ces systèmes pourraient avoir un impact significatif sur la réduction des coûts et sur les temps d'arrêt, sur la maximisation de la fiabilité et de la productivité, sur l'amélioration de la qualité et enfin pour atteindre les objectifs souhaités des compagnies. En outre, les risques et les incertitudes associés à ces systèmes sont souvent composés de plusieurs relations de cause à effet de façon extrêmement complexe. Cela pourrait mener à une augmentation du nombre de défaillances de ces systèmes. Par conséquent, un outil d'analyse de défaillance avancée est nécessaire pour considérer les interactions complexes de défaillance des composants dans les différentes phases du cycle de vie du produit pour assurer les niveaux élevés de sécurité et de fiabilité. Dans cette thèse, on aborde dans un premier temps les lacunes des méthodes d'analyse des risques/échec et celles qui permettent la sélection d'une classe de stratégie de maintenance à adopter. Nous développons ensuite des approches globales pour la maintenance et l'analyse du processus de défaillance fondée sur les risques des systèmes et machines complexes connus pour être utilisées dans toutes les industries. Les recherches menées pour la concrétisation de cette thèse ont donné lieu à douze contributions importantes qui se résument comme suit: Dans la première contribution, on aborde les insuffisances des méthodes en cours de sélection de la stratégie de maintenance et on développe un cadre fondé sur les risques en utilisant des méthodes dites du processus de hiérarchie analytique (Analytical Hierarchy Process (AHP), de cartes cognitives floues (Fuzzy Cognitive Maps (FCM)), et la théorie des ensembles flous (Fuzzy Soft Sets (FSS)) pour sélectionner la meilleure politique de maintenance tout en considérant les incertitudes. La deuxième contribution aborde les insuffisances de la méthode de l'analyse des modes de défaillance, de leurs effets et de leur criticité (AMDEC) et son amélioration en utilisant un modèle AMDEC basée sur les FCM. Les contributions 3 et 4, proposent deux outils de modélisation dynamique des risques et d'évaluation à l'aide de la FCM pour faire face aux risques de l'externalisation de la maintenance et des réseaux de collaboration. Ensuite, on étend les outils développés et nous proposons un outil d'aide à la décision avancée pour prédire l'impact de chaque risque sur les autres risques ou sur la performance du système en utilisant la FCM (contribution 5).Dans la sixième contribution, on aborde les risques associés à la maintenance dans le cadre des ERP (Enterprise Resource Planning (ERP)) et on propose une autre approche intégrée basée sur la méthode AMDEC floue pour la priorisation des risques. Dans les contributions 7, 8, 9 et 10, on effectue une revue de la littérature concernant la maintenance basée sur les risques des dispositifs médicaux, puisque ces appareils sont devenus très complexes et sophistiqués et l'application de modèles de maintenance et d'optimisation pour eux est assez nouvelle. Ensuite, on développe trois cadres intégrés pour la planification de la maintenance et le remplacement de dispositifs médicaux axée sur les risques. Outre les contributions ci-dessus, et comme étude de cas, nous avons réalisé un projet intitulé “Mise à jour de guide de pratique clinique (GPC) qui est un cadre axé sur les priorités pour la mise à jour des guides de pratique cliniques existantes” au centre interdisciplinaire de recherche en réadaptation et intégration sociale du Québec (CIRRIS). Nos travaux au sein du CIRRIS ont amené à deux importantes contributions. Dans ces deux contributions (11e et 12e) nous avons effectué un examen systématique de la littérature pour identifier les critères potentiels de mise à jour des GPCs. Nous avons validé et pondéré les critères identifiés par un sondage international. Puis, sur la base des résultats de la onzième contribution, nous avons développé un cadre global axé sur les priorités pour les GPCs. Ceci est la première fois qu'une telle méthode quantitative a été proposée dans la littérature des guides de pratiques cliniques. L'évaluation et la priorisation des GPCs existants sur la base des critères validés peuvent favoriser l'acheminement des ressources limitées dans la mise à jour de GPCs qui sont les plus sensibles au changement, améliorant ainsi la qualité et la fiabilité des décisions de santé.Today, most systems in various critical sectors such as aviation, oil and health care have become very complex and dynamic, and consequently can at any time stop working. To prevent this from reoccurring and getting out of control which incur huge losses in terms of costs and downtime; the adoption of control and maintenance strategies are more than necessary and even vital. In process engineering, optimal maintenance strategies for these systems could have a significant impact on reducing costs and downtime, maximizing reliability and productivity, improving the quality and finally achieving the desired objectives of the companies. In addition, the risks and uncertainties associated with these systems are often composed of several extremely complex cause and effect relationships. This could lead to an increase in the number of failures of such systems. Therefore, an advanced failure analysis tool is needed to consider the complex interactions of components’ failures in the different phases of the product life cycle to ensure high levels of safety and reliability. In this thesis, we address the shortcomings of current failure/risk analysis and maintenance policy selection methods in the literature. Then, we develop comprehensive approaches to maintenance and failure analysis process based on the risks of complex systems and equipment which are applicable in all industries. The research conducted for the realization of this thesis has resulted in twelve important contributions, as follows: In the first contribution, we address the shortcomings of the current methods in selecting the optimum maintenance strategy and develop an integrated risk-based framework using Analytical Hierarchy Process (AHP), fuzzy Cognitive Maps (FCM), and fuzzy Soft set (FSS) tools to select the best maintenance policy by considering the uncertainties.The second contribution aims to address the shortcomings of traditional failure mode and effect analysis (FMEA) method and enhance it using a FCM-based FMEA model. Contributions 3 and 4, present two dynamic risk modeling and assessment tools using FCM for dealing with risks of outsourcing maintenance and collaborative networks. Then, we extend the developed tools and propose an advanced decision support tool for predicting the impact of each risk on the other risks or on the performance of system using FCM (contribution 5). In the sixth contribution, we address the associated risks in Enterprise Resource Planning (ERP) maintenance and we propose another integrated approach using fuzzy FMEA method for prioritizing the risks. In the contributions 7, 8, 9, and 10, we perform a literature review regarding the risk-based maintenance of medical devices, since these devices have become very complex and sophisticated and the application of maintenance and optimization models to them is fairly new. Then, we develop three integrated frameworks for risk-based maintenance and replacement planning of medical devices. In addition to above contributions, as a case study, we performed a project titled “Updating Clinical Practice Guidelines; a priority-based framework for updating existing guidelines” in CIRRIS which led to the two important contributions. In these two contributions (11th and 12th) we first performed a systematic literature review to identify potential criteria in updating CPGs. We validated and weighted the identified criteria through an international survey. Then, based on the results of the eleventh contribution, we developed a comprehensive priority-based framework for updating CPGs based on the approaches that we had already developed and applied success fully in other industries. This is the first time that such a quantitative method has been proposed in the literature of guidelines. Evaluation and prioritization of existing CPGs based on the validated criteria can promote channelling limited resources into updating CPGs that are most sensitive to change, thus improving the quality and reliability of healthcare decisions made based on current CPGs. Keywords: Risk-based maintenance, Maintenance strategy selection, FMEA, FCM, Medical devices, Clinical practice guidelines

COMPREHENSIVE FRAMEWORKS FOR DECISION MAKING SUPPORT IN MEDICAL EQUIPMENT MANAGEMENT

Throughout medical equipment life cycle, hospitals need to take decisions on medical equipment management based upon a set of different criteria. In fact, medical equipment acquisition, preventive maintenance, and replacement are considered the most important phases, accordingly a properly planned management for these issues is considered a key decision of medical equipment management. In this thesis, a set of frameworks were developed regarding acquisition, preventive maintenance, and replacement to improve management process of medical equipment. In practice, quality function deployment was proposed as a core method around which the frameworks were developed

Criticality evaluation to support maintenance management of manufacturing systems

This paper focuses on criticality evaluation for supporting daily equipment maintenance management and the definition of medium and long-term maintenance actions to improve equipment and, therefore, productivity. These two different purposes led to the development of two different methods for criticality evaluation, using criteria adjusted for each case. The first method is based on rules for defining priorities for corrective and preventive maintenance tasks. Since a failure mode of critical equipment is not necessarily critical, priorities for maintenance tasks are assigned to tasks rather than to equipment. The second method uses Analytic Hierarchy Process to prioritize equipment based on its performance. This method is based on the indicators commonly monitored by maintenance departments. In addition to assessing equipment performance, it considers the maintenance effort made to achieve the evaluated performance. The selection of the criticality criteria and the development of the methods was based on literature review and triggered by a case study in a multinational automotive company. With the integration of the proposed methods in a computerized maintenance management system, maintenance technicians and managers are able to know in real time the tasks that should be performed first and to monitor the overall performance of equipment in the plant, focusing improvements where they are more required.POFC - Programa Operacional Temático Factores de Competitividade (UID/CEC/00319/2013

User needs elicitation via analytic hierarchy process (AHP). A case study on a Computed Tomography (CT) scanner

Background: The rigorous elicitation of user needs is a crucial step for both medical device design and purchasing. However, user needs elicitation is often based on qualitative methods whose findings can be difficult to integrate into medical decision-making. This paper describes the application of AHP to elicit user needs for a new CT scanner for use in a public hospital. Methods: AHP was used to design a hierarchy of 12 needs for a new CT scanner, grouped into 4 homogenous categories, and to prepare a paper questionnaire to investigate the relative priorities of these. The questionnaire was completed by 5 senior clinicians working in a variety of clinical specialisations and departments in the same Italian public hospital. Results: Although safety and performance were considered the most important issues, user needs changed according to clinical scenario. For elective surgery, the five most important needs were: spatial resolution, processing software, radiation dose, patient monitoring, and contrast medium. For emergency, the top five most important needs were: patient monitoring, radiation dose, contrast medium control, speed run, spatial resolution. Conclusions: AHP effectively supported user need elicitation, helping to develop an analytic and intelligible framework of decision-making. User needs varied according to working scenario (elective versus emergency medicine) more than clinical specialization. This method should be considered by practitioners involved in decisions about new medical technology, whether that be during device design or before deciding whether to allocate budgets for new medical devices according to clinical functions or according to hospital department

Hospital energy demand forecasting for prioritisation during periods of constrained supply

Purpose: Sustaining healthcare operations without adequate energy capacity creates significant challenges, especially during periods of constrained energy supply. This research develops a clinical and non-clinical activity-based hospital energy model for electrical load prioritization during periods of constrained energy supply. Design/methodology/approach: Discrete event modelling is adopted for development of the hospital energy model (HEM). The building block of the HEM is business process mapping of a hospitals clinical and non-clinical activities. The model prioritizes the electrical load demand as Priority 1, 2 and 3; Priority 1 activities are essential to the survival of patients, Priority 2 activities are critical activities that are required after one to four hours, and Priority 3 activities can run for several hours without electricity. Findings: The model was applied to small, medium, and large hospitals. The results demonstrate that Priority 2 activities have the highest energy demand, followed by Priority 1 and Priority 3 activities, respectively for all hospital sizes. For the medium and large hospitals, the top three contributors to energy demand are lighting, HVAC, and patient services. For the small hospital, it is patient services, lighting, and HVAC. Research limitations/implications: The model is specific to hospitals but can be modified for other healthcare facilities. Practical implications: The resolution of the electrical energy demand down to the business activity level enables hospitals to evaluate current practices for optimization. It facilitates multiple energy supply scenarios, enabling hospital management to conduct feasibility studies based on available power supply options Social implications: Improved planning of capital expenditure and operational budgets. Improved operations during periods of constrained energy supply, which reduces the risk to hospitals and ensures consistent quality of service. Originality/value: Current hospital energy models are limited, especially for operations management under constrained energy supply. A simple to use model is proposed to assist in planning of activities based on available supplyPeer Reviewe

Decision-Making Framework for Medical Equipment Maintenance and Replacement in Private Hospitals

The process for medical equipment maintenance and replacement in hospitals is a challenging and demanding procedure. Further, the topic of making decisions to maintain or replace or upgrade medical equipment has been debated for a long time since errors equipment maintenance will increase equipment failure at undesirable times; or if early equipment replacement will result in high investment costs and premature disposal. Therefore, standard operating procedures or guidelines need to be in place to help healthcare facilities conduct a more organized and planned maintenance and replacement process. Many hospitals may already have established replacement guidelines or have implemented asset monitoring systems for this purpose. However, the effectiveness of this system has not yet been systematically evaluated. Several studies have been conducted on the same research topic, but most of the findings emphasize the replacement method rather than the criteria that contributed to the decision. Criteria for replacing medical equipment play an important role in ensuring that the equipment can be used cost-effectively. Thus, this research aims to identify important criteria that need to be considered for medical equipment maintenance and replacement focusing on private hospitals. This research was conducted in three phases: (1) a structured literature review; (2) semi-structured interviews with eleven (11) healthcare experts; and (3) a pairwise comparison survey with 50 biomedical engineers. A decision-making framework was developed based on the findings of these three research phases. The framework developed will provide guidelines for practitioners and academics to understand and make better decisions for medical equipment maintenance and replacement in the context of private hospitals

Fuzzy FMECA Process Analysis for Managing the Risks in the Lifecycle of a CBCT Scanner

The Failure Mode, Effects, and Criticality Analysis (FMECA) is one of the risk analysis techniques proposed by the ISO 14971 Standard. This analysis allows to identify and assess the consequences of faults that affect each component of a complex system. The FMECA is a forward-type technique used for highlighting critical points and classifying them by priority. It also makes it possible to evaluate the extent of failures by means of numerical indices. It can be applied to a product or to a work process. In the latter case we talk about Process-FMECA. The application of the Process-FMECA to bioengineering is of particular interest because this procedure provides an analysis related to risk management during all the different phases of the medical device life cycle. However, practical applications of this method have revealed some shortcomings that can lead to inaccuracies and inconsistencies regarding the risk analysis and consequent risk prioritization. This paper presents an example of application of a Fuzzy Process-FMECA, an improved Process-FMECA based on fuzzy logic, to a small computerized tomography (CT) device prototype designed for studying the extremities of the human body. This prototype is a CT device that uses the Cone Beam CT (CBCT) technology. The Fuzzy Process-FMECA analysis has made it possible to produce a table of risks, that are quantified according to the specifications of the method. The analysis has shown that each phase or activity is fundamental to guarantee a correct functioning of the device. The methodology applied to this specific device can be paradigmatic for analyzing the process risks for any other medical device

Prioritization of patients' access to health care services

L'accès aux services de santé et les longs délais d'attente sont l’un des principaux problèmes dans la plupart des pays du monde, dont le Canada et les États-Unis. Les organismes de soins de santé ne peuvent pas augmenter leurs ressources limitées, ni traiter tous les patients simultanément. C'est pourquoi une attention particulière doit être portée à la priorisation d'accès des patients aux services, afin d’optimiser l’utilisation de ces ressources limitées et d’assurer la sécurité des patients. En fait, la priorisation des patients est une pratique essentielle, mais oubliée dans les systèmes de soins de santé à l'échelle internationale. Les principales problématiques que l’on retrouve dans la priorisation des patients sont: la prise en considération de plusieurs critères conflictuels, les données incomplètes et imprécises, les risques associés qui peuvent menacer la vie des patients durant leur mise sur les listes d'attente, les incertitudes présentes dans les décisions des cliniciens et patients, impliquant l'opinion des groupes de décideurs, et le comportement dynamique du système. La priorisation inappropriée des patients en attente de traitement a une incidence directe sur l’inefficacité des prestations de soins de santé, la qualité des soins, et surtout sur la sécurité des patients et leur satisfaction. Inspirés par ces faits, dans cette thèse, nous proposons de nouveaux cadres hybrides pour prioriser les patients en abordant un certain nombre de principales lacunes aux méthodes proposées et utilisées dans la littérature et dans la pratique. Plus précisément, nous considérons tout d'abord la prise de décision collective incluant les multiples critères de priorité, le degré d'importance de chacun de ces critères et de leurs interdépendances dans la procédure d'établissement des priorités pour la priorisation des patients. Puis, nous travaillons sur l'implication des risques associés et des incertitudes présentes dans la procédure de priorisation, dans le but d'améliorer la sécurité des patients. Enfin, nous présentons un cadre global en se concentrant sur tous les aspects mentionnés précédemment, ainsi que l'implication des patients dans la priorisation, et la considération des aspects dynamiques du système dans la priorisation. À travers l'application du cadre global proposé dans le service de chirurgie orthopédique à l'hôpital universitaire de Shohada, et dans un programme clinique de communication augmentative et alternative appelé PACEC à l'Institut de réadaptation en déficience physique de Québec (IRDPQ), nous montrons l'efficacité de nos approches en les comparant avec celles actuellement utilisées. Les résultats prouvent que ce cadre peut être adopté facilement et efficacement dans différents organismes de santé. Notamment, les cliniciens qui ont participé à l'étude ont conclu que le cadre produit une priorisation précise et fiable qui est plus efficace que la méthode de priorisation actuellement utilisée. En résumé, les résultats de cette thèse pourraient être bénéfiques pour les professionnels de la santé afin de les aider à: i) évaluer la priorité des patients plus facilement et précisément, ii) déterminer les politiques et les lignes directrices pour la priorisation et planification des patients, iii) gérer les listes d'attente plus adéquatement, vi) diminuer le temps nécessaire pour la priorisation des patients, v) accroître l'équité et la justice entre les patients, vi) diminuer les risques associés à l’attente sur les listes pour les patients, vii) envisager l'opinion de groupe de décideurs dans la procédure de priorisation pour éviter les biais possibles dans la prise de décision, viii) impliquer les patients et leurs familles dans la procédure de priorisation, ix) gérer les incertitudes présentes dans la procédure de prise de décision, et finalement x) améliorer la qualité des soins.Access to health care services and long waiting times are one of the main issues in most of the countries including Canada and the United States. Health care organizations cannot increase their limited resources nor treat all patients simultaneously. Then, patients’ access to these services should be prioritized in a way that best uses the scarce resources, and to ensure patients’ safety. In fact, patients’ prioritization is an essential but forgotten practice in health care systems internationally. Some challenging aspects in patients’ prioritization problem are: considering multiple conflicting criteria, incomplete and imprecise data, associated risks that threaten patients on waiting lists, uncertainties in clinicians’ decisions, involving a group of decision makers’ opinions, and health system’s dynamic behavior. Inappropriate prioritization of patients waiting for treatment, affects directly on inefficiencies in health care delivery, quality of care, and most importantly on patients’ safety and their satisfaction. Inspired by these facts, in this thesis, we propose novel hybrid frameworks to prioritize patients by addressing a number of main shortcomings of current prioritization methods in the literature and in practice. Specifically, we first consider group decision-making, multiple prioritization criteria, these criteria’s importance weights and their interdependencies in the patients’ prioritization procedure. Then, we work on involving associated risks that threaten patients on waiting lists and handling existing uncertainties in the prioritization procedure with the aim of improving patients’ safety. Finally, we introduce a comprehensive framework focusing on all previously mentioned aspects plus involving patients in the prioritization, and considering dynamic aspects of the system in the patients’ prioritization. Through the application of the proposed comprehensive framework in the orthopedic surgery ward at Shohada University Hospital, and in an augmentative and alternative communication (AAC) clinical program called PACEC at the Institute for Disability Rehabilitation in Physics of Québec (IRDPQ), we show the effectiveness of our approaches comparing the currently used ones. The implementation results prove that this framework could be adopted easily and effectively in different health care organizations. Notably, clinicians that participated in the study concluded that the framework produces a precise and reliable prioritization that is more effective than the currently in use prioritization methods. In brief, the results of this thesis could be beneficial for health care professionals to: i) evaluate patients’ priority more accurately and easily, ii) determine policies and guidelines for patients’ prioritization and scheduling, iii) manage waiting lists properly, vi) decrease the time required for patients’ prioritization, v) increase equity and justice among patients, vi) diminish risks that could threaten patients during waiting time, vii) consider all of the decision makers’ opinions in the prioritization procedure to prevent possible biases in the decision-making procedure, viii) involve patients and their families in the prioritization procedure, ix) handle available uncertainties in the decision-making procedure, and x) increase quality of care

Prioritizacija i procjena ključa sigurnosti pokazatelja uspjeha u automobilskoj industriji

The performance of any management system needs to be monitored with adequate and proper indicators. This study aimed to identify, set priorities and assess key indicators for implementing an effective performance evaluation system. This descriptive-analytical study was carried out in three phase. In first phase, a semi-structured interview as well as a review of the company\u27s documentation and studies carried out, then a set of key indicators were collected and selected. The validity of the indicators were determined by experts (N = 11) and indicators were prioritized using Analytic Hierarchy Process (AHP) according to SMART (Specific, Measurable, Achievable, Relevant, and Time- bound) criteria. Following the study framework, a primary set of 60 Key Performance Indicators (KPIs) were collected. The results of the validity assessment showed 23 indicators had acceptable validity. The results of examining the relationships between the indicators showed that the percentage of corrected non- compliance and the number of risk assessments had a significant relationships with the total number of work-related lost time injuries as a lagging indicator. According to the results, the four the most important key performance indicators to assess the safety performance in the automotive industry were as follows: the number of risk assessments conducted, the percentage of corrected non- compliance, the percentage of safety educational programs implemented for workers, and Frequency Severity Index (FSI) index.Učinkovitost bilo kojeg sustava upravljanja treba pratiti odgovarajućim i ispravnim pokazateljima. Cilj ove studije bio je identificirati, odrediti prioritete i procijeniti ključne pokazatelje za primjenu učinkovitog sustava vrednovanja učinka. Ovo opisno-analitičko istraživanje provedeno je u tri faze. U prvoj fazi, polustrukturirani intervju, kao i pregled provedene dokumentacije i studija tvrtke, zatim je prikupljen i odabran skup ključnih pokazatelja. Valjanost pokazatelja odredili su stručnjaci (N = 11), a pokazatelji su odredili prioritete pomoću Analitičkog postupka hijerarhije (AHP) prema SMART (Specifični, mjerljivi, dostižni, relevantni i vremenski ograničeni) kriteriji. Slijedom okvira studije, prikupljen je primarni skup od 60 KPI. Rezultati procjene valjanosti pokazali su da 23 pokazatelja imaju prihvatljivu valjanost. Rezultati ispitivanja odnosa između pokazatelja pokazali su da je postotak ispravljene neusaglašenosti i broj procjena rizika u značajnoj vezi s ukupnim brojem ozljeda izgubljenog na radu kao pokazatelj zaostajanja. Prema rezultatima, četiri najvažnija ključna pokazatelja uspješnosti za procjenu sigurnosnih performansi u automobilskoj industriji bila su sljedeća: broj provedenih procjena rizika, postotak ispravljenih nesukladnosti, postotak provedenih obrazovnih programa o sigurnosti za radnike i indeks FSI