Risk Assessment of a Wind Turbine: A New FMECA-Based Tool With RPN Threshold Estimation

A wind turbine is a complex system used to convert the kinetic energy of the wind into electrical energy. During the turbine design phase, a risk assessment is mandatory to reduce the machine downtime and the Operation & Maintenance cost and to ensure service continuity. This paper proposes a procedure based on Failure Modes, Effects, and Criticality Analysis to take into account every possible criticality that could lead to a turbine shutdown. Currently, a standard procedure to be applied for evaluation of the risk priority number threshold is still not available. Trying to fill this need, this paper proposes a new approach for the Risk Priority Number (RPN) prioritization based on a statistical analysis and compares the proposed method with the only three quantitative prioritization techniques found in literature. The proposed procedure was applied to the electrical and electronic components included in a Spanish 2 MW on-shore wind turbine

Quality Modeling And Improvement Of University Facilities Services Using Six-Sigma - A Case Study On Wayne State University Fpm Services

Literature survey shows that there is no published information concerning the investigation and/or evaluation (by the customer) of the services provided by universities facilities management units, and no previous research was done to measure and evaluate such services to address, identify, and model the critical factors affecting quality. This research work proposed a service quality model relating factors affecting quality of services provided by facility management units at higher educational institutions to the customer perception of service quality. It also examined the use of the Six-Sigma DMAIC methodology as an improvement strategy for services provided by facility management units at higher education institutions. Based on the service quality model developed and using a tool box of Six-Sigma methods, a case study at Wayne State University (WSU) was performed to examine and improve the facilities services for. A large scale survey was used as an instrument to measure customer satisfaction with the services delivered. The customer ratings for services showed that some service categories needed improvement. The initial service quality model was devised by surveying the literature, as well as conducting in depth interviews with people in the FM field at different levels of management hierarchy. The model was reviewed, refined, modified, and validated by conducting a Nominal Group Technique session, which led to a final proposed service quality model for higher education institutions. A set of Six-Sigma tools and techniques were utilized through different phases of the service process improvement, and to conduct an improvement process for the selected service category of General Improvement Request Form (GIRF). These tools and techniques included process map, Pareto charts, cause and effect matrix, and Failure Mode and Effect Analysis (FMEA). A modified process map was developed to avoid bottlenecks, and eliminate non-value adding activities. Critical tasks affecting process outputs were identified through Cause and Effect Matrix, and all Key Process Input Variables (KPIVs) were rank ordered with respect to the importance of the output variable. Potential failure modes, failure effects, and causes of failure were identified through FMEA. A risk Priority Number (RPN) was assigned for each potential failure mode, and recommended actions to eliminate and control failure modes were developed in this process

Quality of fixed dose artemether/lumefantrine products in Jimma Zone, Ethiopia

Background: Malaria caused by Plasmodium vivax and Plasmodium falciparum is among the major public health problems in most endemic areas of the world. Artemisinin-based combination therapy (ACT) has been recommended as a first-line treatment for uncomplicated Plasmodium falciparum malaria almost in all endemic regions. Since ineffectively regulated medicines in resource limited settings could favour infiltration of poor quality anti-malarial medicines into pharmaceutical supply chain and jeopardize a positive treatment outcome, regular monitoring of the quality of anti-malarial medicines is critical. Thus, the aim of this study was to assess the quality of fixed dose combination (FDC) artemether (ART)/lumefantrine (LUM) tablets available in Jimma zone, Ethiopia. Methods: This study was conducted in Jimma zone, Ethiopia. A total of 74 samples of FDC ART/LUM (20mg ART/120mg LUM) tablets were collected from 27 public facilities. All samples were subjected to visual inspection and the relevant information was recorded. The samples were transported to Jimma University Laboratory of Drug Quality (JuLaDQ) and stored at ambient temperature (20 degrees C to 25 degrees C) until analysis. The Pharmacopoeial conform/non-conform methods and the risk-based Derringer's desirability function approach were employed to assess the pharmaceutical quality of the investigated products. Results: The visual inspection results revealed that there were no signs of falsified in the investigated products. Identification test results of samples indicated that all samples contained the stated active pharmaceutical ingredients (APIs). The results of uniformity of mass indicated that all samples complied with International Pharmacopoeial specification limits. The assay results, expressed as percent label claim (%lc) of ART (89.8 to 108.8%, meanSD=99.1 +/- 3.9%) and LUM (90.0 to 111.9%, mean +/- SD=98.2 +/- 3.8%) revealed that, all samples complied with International Pharmacopoeia acceptance specification limits (i.e. 90-110%lc), except one generic product (IPCA Laboratories Ltd., India) which contains excessive LUM (111.9 +/- 1.7%lc). The risk priority number (RPN) results revealed that assay (RPN=392) is relatively the most critical quality attribute followed by identity (RPN=280) and mass uniformity (40). Quality evaluation based on psycho-physical Harrington's scale revealed that more than 96% of samples were within the acceptable ranges (D >= 0.7-1.0). Conclusions: Both Pharmacopoeial and risk-based desirability function approaches to quality evaluation applied to the investigated products revealed that above 96% FDC ART/LUM tablets circulating in public settings of Jimma zone are of good quality

Criticality Analysis for Maintenance Purposes: A Study for Complex In‐service Engineering Assets

The purpose of this paper is to establish a basis for a criticality analysis, considered here as a prerequisite, a first required step to review the current maintenance programs, of complex in‐service engineering assets. Review is understood as a reality check, a testing of whether the current maintenance activities are well aligned to actual business objectives and needs. This paper describes an efficient and rational working process and a model resulting in a hierarchy of assets, based on risk analysis and cost–benefit principles, which will be ranked according to their importance for the business to meet specific goals. Starting from a multicriteria analysis, the proposed model converts relevant criteria impacting equipment criticality into a single score presenting the criticality level. Although detailed implementation of techniques like Root Cause Failure Analysis and Reliability Centered Maintenance will be recommended for further optimization of the maintenance activities, the reasons why criticality analysis deserves the attention of engineers and maintenance and reliability managers are precisely explained here. A case study is presented to help the reader understand the process and to operationalize the mode

Quality of medicines commonly used in the treatment of soil transmitted helminths and Giardia in Ethiopia: a nationwide survey

Background: The presence of poor quality medicines in the market is a global threat on public health, especially in developing countries. Therefore, we assessed the quality of two commonly used anthelminthic drugs [mebendazole (MEB) and albendazole (ALB)] and one antiprotozoal drug [tinidazole (TNZ)] in Ethiopia. Methods/Principal Findings: A multilevel stratified random sampling, with as strata the different levels of supply chain system in Ethiopia, geographic areas and government/privately owned medicines outlets, was used to collect the drug samples using mystery shoppers. The three drugs (106 samples) were collected from 38 drug outlets (government/privately owned) in 7 major cities in Ethiopia between January and March 2012. All samples underwent visual and physical inspection for labeling and packaging before physico-chemical quality testing and evaluated based on individual monographs in Pharmacopoeias for identification, assay/content, dosage uniformity, dissolution, disintegration and friability. In addition, quality risk was analyzed using failure mode effect analysis (FMEA) and a risk priority number (RPN) was assigned to each quality attribute. A clinically rationalized desirability function was applied in quantification of the overall quality of each medicine. Overall, 45.3% (48/106) of the tested samples were substandard, i.e. not meeting the pharmacopoeial quality specifications claimed by their manufacturers. Assay was the quality attribute most often out-of-specification, with 29.2% (31/106) failure of the total samples. The highest failure was observed for MEB (19/42, 45.2%), followed by TNZ (10/39, 25.6%) and ALB (2/25, 8.0%). The risk analysis showed that assay (RPN = 512) is the most critical quality attribute, followed by dissolution (RPN = 336). Based on Derringer's desirability function, samples were classified into excellent (14/106,13%), good (24/106, 23%), acceptable (38/106, 36%%), low (29/106, 27%) and bad (1/106,1%) quality. Conclusions/Significance: This study evidenced that there is a relatively high prevalence of poor quality MEB, ALB and TNZ in Ethiopia: up to 45% if pharmacopoeial acceptance criteria are used in the traditional, dichotomous approach, and 28% if the new risk-based desirability approach was applied. The study identified assay as the most critical quality attributes. The country of origin was the most significant factor determining poor quality status of the investigated medicines in Ethiopia

High-speed civil transport flight- and propulsion-control technological issues

Technology advances required in the flight and propulsion control system disciplines to develop a high speed civil transport (HSCT) are identified. The mission and requirements of the transport and major flight and propulsion control technology issues are discussed. Each issue is ranked and, for each issue, a plan for technology readiness is given. Certain features are unique and dominate control system design. These features include the high temperature environment, large flexible aircraft, control-configured empennage, minimizing control margins, and high availability and excellent maintainability. The failure to resolve most high-priority issues can prevent the transport from achieving its goals. The flow-time for hardware may require stimulus, since market forces may be insufficient to ensure timely production. Flight and propulsion control technology will contribute to takeoff gross weight reduction. Similar technology advances are necessary also to ensure flight safety for the transport. The certification basis of the HSCT must be negotiated between airplane manufacturers and government regulators. Efficient, quality design of the transport will require an integrated set of design tools that support the entire engineering design team