Maintenance Engineering

This study is motivated by the unexpected failure of a network-based system during the performance of corrective maintenance. This incident highlights the importance of incorporating network connectivity analysis in maintenance planning. This study shows that it is crucial to consider network connectivity when planning maintenance. Procedures to conduct maintenance planning with network connectivity consideration is proposed and discussed

... Suprasad V. Amari, Member, IEEE ... Notation label of component , [failure, repair] rate of component system-failure frequency “mean number of system-failures” per time-unit , Boolean variable indicating that component is [working, failed]; is the complement of , steady state ...

We present a logical framework for modeling and reasoning about the evolution of requirements. We demonstrate how a sufficiently rich meta level logic can formally capture intuitive aspects of managing changes to requirements models, while maintaining completeness and consistency. We consider a theory as the deductive closure of a given set of axioms and conclude that software engineering is concerned, in essence, with, building and managing large theories. This theory construction commences with the development of the requirements model which we view as a theory of some nonmonotonic logic. Requirements evolution then involves the mapping of one such theory to another. Exploiting the deductive power of the theory of belief revision and nonmonotonic reasoning we develop a formal description of this mapping, as well as the requirements engineering process itself. This work thus offers a rigorous approach to reasoning about requirements evolution and a important focus for defining semantically well founded methods and tools for the effective management of changing requirements

In many cases, the manholes for maintaining various installations including power and telecommunication cables, water-, remote heating-, and gas-pipes are located in a close vicinity of power substations. The paper analyzes the risks of the occurrence of dangerous potential differences within the manhole and on the surrounding ground surface during ground faults in the substation. Possible protective measures are discussed.

This paper describes how a database design can play an important role for developing practical industrial maintenance system. The good database design will in return give a better information sharing and good system in term of data accessibility. The design of the database are presented and illustrated by a case. The preliminary result presented to show that is possible to

— Availability of mining machines plays a significant role in mine production. Dragline's reliability has a great impact on sustaining economic feasibility of open cast coal mining projects. In that sense, reliability of draglines and optimizing its preventive maintenance are key issues to be addressed. The objective of this study is to apply machine learning methodologies for classifying failure types of a dragline based on a real data. The mean time between failure data was acquired from an operating open cast coal mine in Turkey. Three modified form of K-Nearest Neighbors algorithms have been used as a predictor for failure classification. An approximation function has been generated based on the time to failure and breakdown type. In case of parameter tuning, cross validation method has been utilized. This caused more reliable evaluation of the test sample, so average testing performance has been used for test data estimation. The basic model was for parameter tuning; Moreover, for achieving more efficient parameter Grid Search method was utilized. Since, usage of the algorithm is computationally expensive, so Randomized Search method has been carried out in order to figure out the functionality of modeled function in the high dimension datasets. The results of the study revealed that the application of K-Nearest Neighbors method reached the Regression Analysis of 73 percent. Thus, the higher accuracy of prediction of failure type can be helpful in prognostic of dragline's procedure. The main novelty of this study is utilization of machine learning approach for dragline maintenance for the first time.

In this paper a set of concepts to design mixed reality systems is presented. The principle of interaction space is proposed and then integrated in a development process, especially, to take into account the mixed reality specifications in the information system design. Models are elaborated to highlight relationships between business and interaction spaces. The development of the proposed method is presented on a case study.

With global cuts in defense budgets, air forces have to sustain the same level of readiness with a reduced number of aircraft. To succeed with this challenge, it is not sufficient to improve current maintenance concepts, but also new ones have to be introduced. Traditionally, the development of on-board functions and maintenance concepts has been performed rather independently. The new

This paper draws an overview of rail passenger service disruptions which lead to service delays. Some findings on the train service delays in some parts of Asia and Western Europe are presented. The types and causes of service disruptions are analyzed across some rail network operators. The equivalent cost measures of delays done by past studies are also discussed. These costs are expressed in terms of monetary and time value. Finally, the benefits obtained from some improvement projects, are briefly addressed. In total, this review suggests that there is an urgent need to minimize service delays for passenger trains, which solution approaches may be obtained from a mathematical model.

Security facilities of information systems with high security requirements should be consistently and continuously developed, used, and maintained based on some common standards of information security. However, there is no engineering environment that can support all tasks in security engineering consistently and continuously. To construct a security engineering environment, a database that can manage all data concerning all tasks in

Software development processes are one of key success factors in software development industries. A good process has to be sound, repeatable, predictable and measurable, but also well documented and well known to all parties involved. It is not easy to define a good aligned process nor to implement it successfully in everyday usage. This paper introduces a company model used in everyday work of a software implementing and developing company dealing with ERP (Enterprise Resource Planning) and CRM (Customer Relationship Management) businesses. The model is based on generic software development models, with modifications following specific business requirements. The company model objectives and goals are trying to be met by proper software development process, model structure and its implementation. The value of the model is estimated on two years' experience in model usage. The results show significant advantages in various areas, from internal organization, customer satisfaction ...

This case study illustrates the potential benefits and risks associated with the migration of an IT system in the oil & gas industry from an in-house data center to Amazon EC2 from a broad variety of stakeholder perspectives across the enterprise, thus transcending the typical, yet narrow, financial and technical analysis offered by providers. Our results show that the system infrastructure in the case study would have cost 37% less over 5 years on EC2, and using cloud computing could have potentially eliminated 21% of ...

This case study illustrates the potential benefits and risks associated with the migration of an IT system in the oil & gas industry from an in-house data center to Amazon EC2 from a broad variety of stakeholder perspectives across the enterprise, thus transcending the typical, yet narrow, financial and technical analysis offered by providers. Our results show that the system infrastructure in the case study would have cost 37% less over 5 years on EC2, and using cloud computing could have potentially eliminated 21% of ...