A BIM-based PSS approach for the management of maintenance operations of building equipment

The service-centered economy has grown considerably in the last few years, shifting from product-based solutions towards service centered offerings, i.e., Product-Service System (PSS) solutions. Such an approach is also emerging in the context of building equipment, where maintenance activities play a fundamental role in facility management. In this field, Building Information Modeling (BIM) based tools are diffusely used to improve the performances of facility management. However, few studies have addressed the above issues while considering a shift from product-based approaches in favor of more advanced servitization models. The study aims at integrating BIM based approaches in a PSS context for the improvement of the management of maintenance operations of building equipment. A general framework for maintenance management has been developed, merging the implementation of the PSS components in a BIM model for the definition of maintenance management. A first application of this methodology to a real case study concerning the elevators of an existing building has shown the efficacy of the proposed approach. The study highlighted the benefits that can be achieved, especially in terms of reduced periods of equipment unavailability, reduced costs and augmented customer satisfaction, while enhancing the information exchange between the PSS actors. Hence, although further research is still needed for its validation, the proposed approach can offer practical insights for the development of promising BIM-based PSS solutions for facility management in the construction industry

Bridges Structural Health Monitoring and Deterioration Detection Synthesis of Knowledge and Technology

INE/AUTC 10.0

Maintenance management of tractors and agricultural machinery: Preventive maintenance systems

Agricultural machinery maintenance has a crucial role for successful agricultural production.  It aims at guaranteeing the safety of operations and availability of machines and related equipment for cultivation operation.  Moreover, it is one major cost for agriculture operations.  Thus, the increased competition in agricultural production demands maintenance improvement, aiming at the reduction of maintenance expenditures while keeping the safety of operations.  This issue is addressed by the methodology presented in this paper.  So, the aim of this paper was to give brief introduction to various preventive maintenance systems specially condition-based maintenance (CBM) techniques, selection of condition monitoring techniques and understanding of condition monitoring (CM) intervals, advancement in CBM, standardization of CBM system, CBM approach on agricultural machinery, advantages and disadvantages of CBM.  The first step of the methodology consists of concept condition monitoring approach for the equipment preventive maintenance; its purpose is the identification of state-of-the-art in the CM of agricultural machinery, describing the different maintenance strategies, CM techniques and methods.  The second step builds the signal processing procedure for extracting information relevant to targeted failure modes.   Keywords: agricultural machinery, fault detection, fault diagnosis, signal processing, maintenance managemen

Probability of Failure of Safety-Critical Systems Subject to Partial Tests

A set of general formulas is proposed for the probability of failure on demand (PFD) assessment of MooN architecture (i.e. k-out-of-n) systems subject to proof tests. The proof tests can be partial or full. The partial tests (e.g. visual inspections, partial stroke testing) are able to detect only some system failures and leave the others latent, whereas the full tests refer to overhauls which restore the system to an as good as new condition. Partial tests may occur at different time instants (periodic or not), up to the full test. The system performances which are investigated are the system availability according to time, the PFD average in each partial test time interval, and the total PFD average calculated on the full test time interval. Following the given expressions, parameter estimations are proposed to assess the system failure rates and the partial test effectiveness according to feedback data from previous test policies. Subsequently, an optimization of the partial test strategy is presented. In the 2oo6 system given as example, an improvement of about 10% of the total PFD average has been obtained, just by a better (non-periodic) distribution of the same number of partial tests, in the full test time interval

Managing Environmental, Health, and Safety Risks: A Comparative Assessment of the Minerals Management Service and Other Agencies

This study compares and contrasts regulatory and related practices—in particular, regulatory decisionmaking, risk assessment and planning processes, inspection and compliance, and organization structure, budgets, and training—of the Minerals Management Service (MMS, now the Bureau of Ocean Energy Management, Regulation, and Enforcement, or BOEMRE) with those of the Federal Aviation Administration (FAA) and the Environmental Protection Agency (EPA). Comparing MMS practices with those of other federal agencies that also manage low-probability but high-consequence environmental risks provides a basis for identifying opportunities for enhancing regulatory capacity and safety performance in managing deepwater energy exploration and production. Our research finds important differences in processes for setting standards; peer review contribution to the rulemaking process; establishment of tolerable risk thresholds; and training of key staff. The paper concludes with several recommendations for how various EPA and FAA practices might be modified and used at BOEMRE to strengthen its regulatory and risk management processes.Minerals Management Service, Federal Aviation Administration, Environmental Protection Agency, risk management

An Improved Estimation of Multiple-Point Fault Probabilities if the Faults Have Different Periodic Latencies

Fault tree analysis (FTA), reliability block diagrams (RBD) and event tree analysis (ETA) are established methods for assessing potential risks of hazardous events, in particular when resulting from coincidental events. Combining the Boolean algebra, probability theory and reliability data, they allow quantitative estimation of intrinsic risks from technical equipment like machinery control, aerospace systems or vehicle functions, among many others. The quantitative reliability theory was mainly developed between the 1960s and the 1980s. At that time, simplifications and approximations for the mathematical formulae were needed to achieve calculation results within acceptable time, regarding restricted computer resources. Our investigation revealed that some of these simplifications and approximations, often assumed as precise calculations in secondary literature, can lead to wrong results in quantitative risk assessment. When faults are combined, and individual latency periods exist, the currently established approximations may lead to results which are too optimistic in comparison with a precise probabilistic approach. This publication proposes a new approximation for the computation of the related probabilities. The approach provides an upper-bound estimation. Using the developed formulae, the under-estimation of multipleevent probabilities can be avoided. In addition, certain vagueness and over-simplification in the probabilistic treatment of events with latency periods can be eliminated. Examples of related shortcomings in the literature can be found, down to the early roots of reliability theory