Risk-based Maintenance Approach Research Articles

Application the Risk-Based Maintenance for Optimizing the Overall Medical Devices Safety

The purpose of this study was to identify risks to patients as a result of sudden device failure during the delivery of medical treatment services. Which, can affect the reputation of hospitals following the exposure of patients' lives to various risks like death, injury, and misdiagnosis. Furthermore, a sudden failure will lead to increased economic losses as a result of increased maintenance costs. Of (20) medical devices, (6) high-risk devices were selected, such as a ventilator, diathermy, anesthesia, BiPAP, oxygen concentrator, and electrosurgical devices. A quantitative statistical analysis based on risk-based maintenance is used to evaluate the effectiveness of the reliability of the medical device and its risks to patient lives. The results show that the reliability of the chosen medical device has declined, with higher maintenance costs due to excessive maintenance or the type of maintenance policy used. Therefore, this study provides evidence that hospitals must adopt a risk-based maintenance approach to prevent sudden failure while in service. In addition, these medical devices have various complex parts that must adopt a combination of maintenance schedules. Based on Risk-Based Maintenance's experience in improving patient safety in public hospitals in the 20 most successful OECD countries.

Development of a risk-based maintenance decision making approach for automotive production line

Automotive industries require effective and reliable maintenance strategies to ensure high levels of availability and safety. Risk-based maintenance approach is a useful tool for maintenance decision making with the aim of reducing the overall risk in operating activities. In this paper, a Failure Mode and Effect Analysis (FMEA) model as one of the risk assessment techniques is developed with subjective information derived from domain experts. To overcome the drawbacks of traditional FMEA for risk priority number (RPN) estimation, a linguistic fuzzy set theory, through effective decision attributes in complex automotive equipment is conducted. The main attributes of this approach include the effect of experts’ traits, scales variation, using various membership functions and defuzzification algorithms on reliable Fuzzy-RPN (FRPN) estimation. The result of the proposed model revealed that altering membership functions and defuzzification algorithms had no significant effect on the FRPN estimation, but their values are highly affected by the number of scales. The sensitivity analysis showed that experts’ traits have no sensible impact on experts’ opinion for FRPN estimation, while the detectability index has more impact on FRPN variation. The result of risk classification number showed that the maintenance decision making could be included for the failure modes with the highest RPN values as a priority, which it would be useful to achieve the high level of availability and safety.

A Risk-Based Approach to Automate Preventive Maintenance Tasks Generation by Exploiting Autonomous Robot Inspections in Wind Farms

In this paper, we dealt with some problems of operation and maintenance in wind farms. We focused on the main critical aspects of any maintenance strategy, which must include the identification of the plant elements to inspect as well as the planning of the possible actions aimed at minimizing production losses. At the same time, any maintenance strategy must take into account the possible costs. In fact, those decisions can be made based on risk-based methods. We designed a risk-based maintenance approach to plan inspection tasks to be assigned to service robots in wind power plants. A supervisory control and data acquisition (SCADA) system is employed to collect and manage suitable data (power, wind velocity, and related machine events), and the risk is evaluated on a daily basis over the data collected. The evaluation of the risk is strictly related to the healthiness of the power plant itself. Then, the tasks are created and scheduled based on a certain priority, which is strictly correlated with the evaluated risk. For the analysis of our approach, we used the real data collected on a wind power plant in Greece over 396 days. The power plant is capable to produce an overall power of 7.2 MW, and it is composed of eight wind turbines of 900 KW per each. We observed that, out of 396 days, 50 days presented machine events leading to a related risk evaluation for which our approach will produce 258 inspection tasks. From this analysis, we conclude that the application of the risk-based methodology paired with the exploitation of permanent robots on the field could result in a 225-MWh reduction of the plant's lost production, in other words, an increase of production of 45.6%.

A risk-based maintenance approach for critical care medical devices: a case study application for a large hospital in a developing country

The availability of specialized medical equipment plays a critical role in the delivery of healthcare services. This becomes even more critical in developing countries where few medical devices are available in public hospitals, hence do not commensurate with demand, which leads to their overutilization. This often results in frequent failure of the medical devices and as a result, low availability. In turn, this leads to delayed treatment and consequently, access to affordable and quality healthcare by the disadvantaged in the society. This rather high unavailability of critical medical equipment in public hospitals in developing countries motivates this study, hence the necessitating the need to implement optimal maintenance strategies and operational protocols for maximizing equipment availability. However, selecting such optimal maintenance and operation strategies is not straightforward, and for this reason, a risk-based maintenance approach is proposed. The proposed approach addresses the aforementioned challenge through structured steps through which maintenance practitioners identify and prioritize prevalent failure modes. Based on the prioritized failure modes, operation and maintenance protocols may be derived. Moreover, the risk-based maintenance approach is useful for among other decisions, root cause analysis. The proposed risk-based maintenance approach consists of four steps; (1) data collection and standardization process, (2) modified failure mode and effect analysis step for prioritizing critical failure modes, (3) a root cause analysis step for analyzing the causes of recurrent failure modes, and (4) formulation of operation and maintenance strategies for mitigating equipment failure risks. The proposed approach is demonstrated in application in a case of large teaching and referral hospital in Kenya.

Risk-Based Maintenance Optimization of Deteriorating Bridges

Risk-based performance measures integrate probability of component or system failure with the consequences of this event. In this paper, a novel risk-based maintenance optimization methodology for deteriorating bridges to find the optimum maintenance options and their timing is proposed. Finding the optimum maintenance types and schedule for different components of bridges is formulated as a multicriteria optimization in which the lifetime maximum value of expected losses associated with failure and the lifetime total expected maintenance cost are considered as the conflicting objectives. The risk-based maintenance approach accounts for different deterioration levels of bridge components and consequences of both component failure and system failure. The methodology is illustrated on a bridge superstructure. The effects of considered life span of the structure and availability of maintenance options on optimum solutions are also investigated.

Development of an empirical formula for machine classification: Prioritization of maintenance tasks

Continuous type production and discrete type manufacturing systems face challenges in optimizing the maintenance related costs. The risk based maintenance approach has been carried out within the continuous type production systems to classify equipment in production and process facilities based on the risk of failure that can cause financial, societal and environmental challenges to the asset owner. At the same time the term ‘machine classification’ (MC) has been used within the discrete type manufacturing systems to classify machines based on the influence on; production process to continue, delay in deliveries, product quality as well as personnel, process, societal and environmental safety. Initially, this paper discusses the role of the MC in mitigating health, safety and environmental challenges. Then, it derives an empirical formula performing classification of machines. The derivation has been performed by carrying out a case study in three manufacturing companies and utilizing the three different MC models employed by them. Finally, the manuscript verifies the empirical formula with an arbitrarily selected manufacturing organization.

An enterprise risk management framework for evaluation of eMaintenance

Maintenance is one approach to managing risk by a reduction of the probability of failure of technical systems and/or the consequences of their failure. However, history has shown that erroneous maintenance also can lead to reduced quality, incidents and accidents with extensive losses. Today, eMaintenance promises great opportunities for a paradigm shift from a rather narrow, condition-based maintenance approach with focus on a technical system’s health to a true risk-based maintenance approach that also considers organizational excellence. This is achieved by proper information logistic solutions that address the needs of all stakeholders of the maintenance process, which are possible due to new and innovative information and communication technology (ICT). However, all opportunities are also linked with some threats, which are seldom highlighted in the case of eMaintenance. In this article, a risk management framework for evaluation of eMaintenance solutions is proposed. The framework is based on a combination of international standards (e.g. ISO 31000, ISO/IEC 27000, and IEC (2004) 60300-3-14) to achieve integrated Enterprise Risk Management (ERM) and enable a linkage of eMaintenance to the strategic goals of an organization. The framework is illustrated in the railway context of Trafikverket (2010b) (the Swedish Transport Administration).

Risk-based maintenance strategy and its applications in a petrochemical reforming reaction system

Risk-based maintenance (RBM) strategy can be used in developing a cost-effective maintenance plan to make financial and safety improvements in a petrochemical system. Most maintenance is imperfect in process industries. Previous works on RBM did not consider imperfect maintenance and thus could hardly meet the engineering requirements of process industries. An improved RBM approach based on the proportional age reduction model is proposed in this paper. The parameters of the failure distribution and maintenance effect of equipment are estimated by maximum likelihood estimation. The financial risk for each subsystem is estimated and compared with the risk criteria. Under the risk constraints, the proper interval of periodic preventive maintenance is determined for the equipment in high-risk subsystems. The case of a reforming reaction system in a petrochemical plant is studied using the improved RBM approach. The results show most equipment in this system is imperfectly repaired. The imperfect nature of the periodic preventive maintenance means it needs to be carried out more frequently.

A risk based maintenance approach (for facilities complying with the US OSHA PSM regulation)

Every US OSHA 29 CFR1910.119 Process Safety Management regulated manufacturing facility is populated with equipment that requires appropriate maintenance to fulfill its role in manufacturing and to keep the facility operating in a safe and environmentally sound manner. However, not all equipment poses the same risks at failure when compared to those requirements. Therefore, from a risk perspective, not all equipment deserves the same level of maintenance attention. Proper categorization of risks and appropriate levels of maintenance attention help keep the facility operating safely by better allocating available resources where and when needed. This paper proposes an approach for establishing a hierarchy of maintenance attention based on various equipment failure risks. It does so by helping the reader to understand the difference between “Mechanical Integrity” and “Reliability” and the risks imposed by failure of either. A combination of different maintenance philosophies, such as preventive, predictive, and run-to-failure/breakdown, is discussed as possible approaches for allocating limited resources.

Risk-based maintenance of gas expansion turbines in steel plant

Unexpected failures, loss of production, higher maintenance costs and down time associated with the failures of equipment are major problems in any plant. Adopting the risk-based maintenance (RBM) approach helps in designing an alternative strategy to minimise the loss resulting from these breakdowns or failures. The methodology consists of four modules: system definition, risk assessment, risk acceptance criterion and maintenance planning. In this study, the RBM approach was adopted for a gas expansion turbine of a steel plant. The resultant risk of the system was found to be unacceptable. Amongst the eight units (subsystems) comprising the system, only two units namely, the governing system and rotor blades, are responsible for such a high risk situation. A risk based maintenance schedule (maintenance intervals) was proposed for the components of the two subsystems. It is observed that the new RBM scheme, if used properly, would bring down the unacceptable level of risk to the desired level.