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Considering that complex equipment and systems are generally repairable, contain redundancy and must be safe, the term reliability appears often for reliability, availability, maintainability, and safety. RAMS is used to point out this wherever necessary in this book. The purpose of reliability engineering is to develop methods and tools to assess RAMS figures of components, equipment and systems, as well as to support development and production engineers in building in these characteristics. In order to be cost and time effective, reliability (RAMS) engineering must be integrated in the project activities, support quality assurance and concurrent engineering efforts, and be performed without bureaucracy. This chapter introduces basic concepts, shows their relationships, and discusses the tasks necessary to assure quality and reliability (RAMS) of complex equipment and systems with high quality and reliability (RAMS) requirements. A comprehensive list of definitions with comments is given in Appendix A1. Standards for quality and reliability (RAMS) assurance are discussed in Appendix A2. Refinements of management aspects are in Appendices A3 - A5. Risk management is considered in Sections 1.2.7 and 6.11.

Poor design of software services results in unnecessarily complex and inflexible SOA applications that are difficult to maintain and evolve. There is also some evidence that the quality of service-oriented applications degrades and as complexity increases with new service versions that include modifications to rectify problems and improve functionality. Design quality metrics play an important role in identifying software quality issues early in the software development lifecycle. The concept of software entropy has been used in literature to express decline in the quality, maintainability and understandability of software through its lifecycle. In this paper we propose a Service Entropy Metric (SEM) that estimates the complexity of service design based on the complexity of the XML message structures that form the basis for service interfaces. We illustrate the application of the SEM metric using the Open Travel Alliance specification and show that the complexity of the specification as measured by SEM increases over time as new versions of the specification are released.

Unifying similar model transformation rules into variability-based ones can improve both the maintainability and the performance of a model transformation system. Yet, manual identification and unification of such similar rules is a tedious and error-prone task. In this paper, we propose a novel merge-refactoring approach for automating this task. The approach employs clone detection for identifying overlapping rule portions and clustering for selecting groups of rules to be unified. Our instantiation of the approach harnesses state-of-the-art clone detection and clustering techniques and includes a specialized merge construction algorithm. We formally prove correctness of the approach and demonstrate its ability to produce high-quality outcomes in twoi¾źreal-lifei¾źcase-studies.

The research shows that maintenance of enterprise information systems consumes about 65---75i¾?% of the software development time and about 40---60i¾?% of maintenance efforts are devoted to software understanding. This paper compares the Anemic Domain Model used by the three-layered architecture followed by Java EE and .NET platforms and the Rich Domain Model often deployed into many conventional MVC-like web frameworks to a novel Aspect Domain Model followed by the Aspect-driven design. While all these models strive to avoid information restatement, they greatly differ in the underlying idea and resulting efficiency. This research compares considered models based on development efficacy, maintainability and their impact on the rest of the system. We evaluate qualities such as information cohesion, coupling and restatement, and discuss related maintenance efforts of the novel approach in the context of existing approaches.

The development framework is the basic and core software resource which can provide a general and reusable structure among all the software applications. This paper proposes a rapid development framework (RDF) of enterprise information system based on software components and JavaEE, the paper not only describes the framework’s structure and the detailed functions of each parts in RDF, but also gives an application example. The development practice proves that this framework has good maintainability, extendibility and stability, it can meet the development needs of most software applications.

An increasingly large number of HPC systems rely on heterogeneous architectures combining traditional multi-core CPUs with power efficient accelerators. Designing efficient applications for these systems has been troublesome in the past as accelerators could usually be programmed only using specific programming languages – such as CUDA – threatening maintainability, portability and correctness. Several new programming environments try to tackle this problem; among them OpenACC offers a high-level approach based on directives. In OpenACC, one annotates existing C, C++ or Fortran codes with compiler directive clauses to mark program regions to offload and run on accelerators and to identify available parallelism. This approach directly addresses code portability, leaving to compilers the support of each different accelerator, but one has to carefully assess the relative costs of potentially portable approach versus computing efficiency. In this paper we address precisely this issue, using as a test-bench a massively parallel Lattice Boltzmann code. We implement and optimize this multi-node code using OpenACC and OpenMPI. We also compare performance with that of the same algorithm written in CUDA, OpenCL and C for GPUs, Xeon-Phi and traditional multi-core CPUs, and characterize through an accurate time model its scaling behavior on a large cluster of GPUs.

For characteristics of reliability, maintainability, supportability and multi-state about a navigation monitor network under real environment, Petri net (PN) and Bayesian network (BN) are applied integrated to availability modeling and analysis of a navigation monitor network in this paper. The relationship of equipments and MTBF, MTTR, MADT, sufficiency, MSRT of spaces are combined for availability modeling of monitor stations by PN. According to normal, degraded and failed states of monitor stations, availability modeling of the monitor network are obtained by BN. By analysis, nominal availability, degraded availability and failed state probability of the monitor network and weakness of monitor stations are confirmed. The multiple schemes are proposed and compared for improving availability. The result shows, improving sufficiency plays a more role in improving availability under real environment, and this method can be used for availability modeling and analysis.

Wind turbines (WT) maintenance management is in continuous development to improve the reliability, availability, maintainability and safety (RAMS) of WTs, and to achieve time and cost reductions. The optimisation of the operation reliability involves the supervisory control and data acquisition to guarantee correct levels of RAMS. A fault detection and diagnosis methodology is proposed for large-scale industrial WTs. The method applies the wavelet and Fourier analysis to vibration signals. A number of turbines (up to 3) of the same type will be instrumented in the same wind farm. The data collected from the individual turbines will be fused and analysed together in order to determine the overall reliability of this particular wind farm and wind turbine type. It is expected that data fusion will allow a significant improvement in overall reliability since the value of the information gained from the various condition monitoring systems will be enhanced. Effort will also focus on the successful application of dependable embedded computer systems for the reliable implementation of wind turbine condition monitoring and control technologies.

Tools are the fundamental requirement for acceptability of any metrics programme in the software industry. It is observed that majority of the metrics proposed and are available in the literature lack tool support. This is one of the reasons why they are not widely accepted by the practitioners. In order to improve the acceptability of proposed metrics among software engineers that develop Web applications, there is need to automate the process. In this paper, we have developed a tool for computing metrics for Cascading Style Sheets (CSS) and named it as CSS Analyzer (CSSA). The tool is capable of measuring different metrics, which are the representation of different quality attributes: which include understandability, reliability and maintainability based on some previously proposed metrics. The tool was evaluated by comparing its result on 40 cascading style sheets with results gotten by the manual process of computing the complexities. The results show that the tool computes in far less time when compared to the manual process and is 51.25% accurate.

High-level languages come with significant readability and maintainability benefits. Their performance costs, however, are usually not predictable, at least not easily. Programmers may accidentally use high-level features in ways that compiler writers could not anticipate, and they may thus produce underperforming programs as a result.

Indoor positioning systems are increasingly being deployed to enable indoor navigation and other indoor location-based services. Systems based on Wi-Fi and video cameras rely on different technologies and techniques and have so far been developed independently by different research communities; we show that integrating information provided by a video system into a Wi-Fi based system increases its maintainability and avoid drops in accuracy over time. Specifically, we consider a Wi-Fi system that uses fingerprints measurements collected in the space for positioning. We improve the system’s room-level accuracy by means of automatic, video-driven collection of fingerprints. Our method is able to relate a Wi-Fi user to unidentified movements detected by cameras by exploiting the existing Wi-Fi system, thus generating fingerprints automatically. This use of video for fingerprint collection reduces the need for manual collection and allows online updating of fingerprints. Hence, increasing system accuracy. We report on an empirical study that shows that automatic fingerprinting induces only few false positives and yields a substantial accuracy improvement.

Model transformation plays a central role in Model-Driven Engineering. In application scenarios such as tool integration or view specification, bidirectionality is a crucial requirement. Triple Graph Grammars (TGGs) are a formally founded, bidirectional transformation language, which has been used successfully in various case studies from different applications domains. In practice, supporting the maintainability of TGGs is a current challenge and existing modularity concepts, e.g., to avoid pattern duplication in TGG rules, are still inadequate. Existing TGG tools either provide no support at all for modularity, or provide limited support with restrictions that are often not applicable. In this paper, we present and formalize a novel modularity concept for TGGs: Rule refinement, which generalizes existing modularity concepts, solves the problem of pattern duplication, and enables concise, maintainable specifications.

As the maintainability and reliability of new helicopter have been greatly improved, the domestic users directly realize some new characteristics of maintenance work. The investigation of characteristics and impact of new helicopter maintenance on the current domestic maintenance work are performed in this paper. Firstly, the analytical results show that the troubleshooting work becomes simpler; condition-based maintenance (CBM) and “changing parts maintenance” have become the inevitable trend for new helicopter maintenance. Secondly, for the impact on maintenance work, the current system of maintenance work and profession division is facing challenge; some maintenance profession has been marginalized; on the contrary, there are some new vacancy profession for maintenance should be filled. Finally, some suggestions of maintenance theory, technology method and maintenance system are brought forward.

Compressor rotor blade is one of the key components of aeroengine. Fan blades and compressor blades rotate at high speed when engine works. They used to be damaged by foreign objects. This paper studies how to grind blades with the use of video endoscopy and grinding devices in the installed state. The study aims to reduce maintenance costs and improve maintenance efficiency, thus improving the maintainability of the aeroengine.

Aimed at the problems of low level of informatization in LaiWu blackpig process and the old way of using paper for date storage, in order to speed upthe informatization development of the process, the LaiWu black pig information management system based on ExtJS is designed. In this paper, the design and realization of the system, as well as the open source framework is illustrated in detail, the ExtJS+SSH(Sturts+Spring+Hibernate)framework exploration model is put forward,and the separation of page and is realized. The result of system operation shows that not only the level of informatization in LaWu black pig process is improved, but also its maintainability and expandability are developed.

Using probability method, mathematical model of mission effectiveness for tanker aircraft is established based on operation service condition. It is a feasible model to demonstrate indicators for tanker aircraft reliability, maintainability and supportability (RM&S). Quantitative evaluation for RM&S factors effect on tanker aircraft in combat can be calculated and analyzed. A concrete example is given to show the model is valuable. Tanker aircraft RM&S demonstration process is greatly simplified, and the demonstration effectiveness is vastly advanced.

Traditional manual modeling and analysis method cannot meet today’s requirements of high-tech equipment for reliability and maintainability. The RCM-analysis methods proposed to study the reliability of electronic equipment, as well as reliability allocation method. We use Lambda Predict microcontroller-based instrumentation and control equipment part of the circuit to set up the model and make a reliability prediction analysis and reliability allocation study. At last, we get the expected results of the analysis equipment reliability.

Nonstandard aeronautical testing equipment is important to ground testing of airplane. Its reliability and maintainability have influence on the composite supportability of the aircraft directly. Because nonstandard testing equipment has a series of characteristics with complex, short development cycle, and small quantity, so the reliability and maintainability of equipment is affected. The statistics of failure generated by reliability and maintainability is carried out in this paper, and the causes are also analyzed. The measurement and method of developing reliability and guaranteeing supportability comprehensively for the nonstandard aeronautical testing equipment are discussed in the links of design, manufacture, use, management, and so on.

Part of Academia's motivation for improving agent-based languages and architectures is the hope that some of its solutions might be, one day, adopted by the videogame industry for specification of agents' behavior. However, the games industry already employs its own techniques for that purpose. Thus we need rigorous empirical data to provide an insight to the expected utility of academic solutions and pinpoint their most promising features. Game pro-grammers often face situations when they have to understand and modify the work of current or former colleagues, or to extend their own work from months or even years ago. Thus, one way an academia's solution could provide value would be that it outperforms the industry's typical approach under these circumstances --- offering better code readability and maintainability. Here we present results of an empirical study modeling this problem. We adopt Java programming as the industry approach (modeling scripting) and choose the POSH reactive planner as an academic approach. We engaged 22 computer science students attending a university course on virtual agents on two programming assignments, in which they had to produce specific high-level behaviors of 3D virtual agents solving different game-like tasks. First, students had to produce the behavior of a particular task from scratch. Second, these behaviors were used in an assignment where students had to extend the behavior coded by someone else. Finally, three months later, 8 of these students were told to extend their own behavior they coded in the first assignment. The quantitative results indicate that Java is as good as POSH in terms of subjective programmers' preference and that there is no objective difference between qualities of created behaviors. The qualitative results suggest several useful but also troublesome features of POSH, some of which are shared by other languages, suggesting possible improvements.

For the development of high quality software, process quality assessment should be applied into development organization. So far, several process quality assessment methodologies are proposed and applied into a lot of organizations. In this paper, we propose an approach to assess instances of refactoring that is one of the key processes for quality improvement. The proposed approach can be done semi-automatically by investigating version archives in a configuration management system. We applied our proposed method to the Columba project which is an open source software project. The result of our preliminary case study shows that the frequency of defect introduction tends to decrease in the term after frequent refactoring.

The present paper focuses on maintaining one’s data secrecy in cloud storage area and it may depend on their privacy policy and standards. The effectiveness and efficiency of preserved data from different cloud providers should maintain the integrity of original data stored in it. In the era of could computing, stored information’s value, proficiency and optimization of data retrieving spotlights the importance of maintaining cloud users data, privacy, identity, reliability and maintainability it may vary for different Cloud providers (CP). Giant CP ensures their user proprietary information’s are sustained more secretly using cloud technologies. During third party cloud services and exodus between inter cloud providers may lead to data portability privacy issue. More remarkable event in this case, even the cloud providers don’t have implication about the information and records where it’s stored and maintained in their own cloud. This is one of the obligatory research issue in cloud computing. We came frontward by proposing (EMPPC) an Evolutionary model based privacy Preserving technique and try to hold user’s, to have trust in providers for maintaining their confidentiality in cloud. This proposal helps the CR (Cloud Requester and Users) to mark trust on their proprietary information and data’s stored in cloud.

The software architecture of a system is often used to guide and constrain its implementation. While the code structure of an initial implementation is likely to conform to its intended architecture, its dynamic properties cannot be fully checked until deployment. Routine maintenance and changing requirements can also lead to a deployed system deviating from this architecture over time. Both static and dynamic checks are thus required to ensure that an implementation conforms to its prescriptive architecture throughout its lifespan. However, runtime conformance checking strategies typically alter the implementation of an application, increasing its size and affecting its performance and maintainability. In this paper, we describe the design of a novel dynamic conformance-checking framework that is pluggable and non-intrusive, thereby limiting any overheads to those periods when checking is activated. An implementation of this framework with Java as the target language and its early evaluation are also presented.

Many seismological software applications are developed to support for instance studies of earthquake scenarios, seismic exploration surveys or hazard analysis. Most of these applications were developed in isolation with focus on algorithmic performance, and less emphasized on software’s comprehensibility and maintainability. However, requirements engineering practices, which help to describe the applications from a high level point of view, are mostly ignored. As a result, trying to reuse these algorithms in larger systems, developers face difficulties in comprehending, modifying, adapting and integrating the applications. This paper presents our work of introducing the concepts of requirements engineering to seismological research projects. Requirements describe what a software system is expected to do and to be. They are used to communicate between scientists from different domains (e.g. seismology and computer science) to achieve a common understanding for developing the software. Requirements also provide a basis for other development activities, such as software comprehension, software design, implementation and maintenance. We present a model-based requirements engineering approach that incorporates abstractions and notations from the seismology domain. We describe two requirements patterns, which facilitate the identification and specification of requirements in seismological software development. We use a dynamic rupture example to illustrate how seismologists can apply our approach.

In safety analysis for safety-critical embedded systems, methods such as FMEA and fault trees (FT) are strongly established in practice. However, the current shift towards model-based development has resulted in various new safety analysis methods, such as Component Integrated Fault Trees (CFT). Industry demands to know the benefits of these new methods. To compare CFT to FT, we conducted a controlled experiment in which 18 participants from industry and academia had to apply each method to safety modeling tasks from the avionics domain. Although the analysis of the solutions showed that the use of CFT did not yield a significantly different number of correct or incorrect solutions, the participants subjectively rated the modeling capacities of CFT significantly higher in terms of model consistency, clarity, and maintainability. The results are promising for the potential of CFT as a model-based approach.

The software systems have been exposed to constant changes in a short period of time. It requires high maintainable systems and makes maintainability one of the most important quality attributes. In this work we performed a statistical analysis of maintainability metrics in three mainstream open-source applications, Tomcat (webserver), Jedit (text editor) and Vuze (a peer to peer client). The metrics are applied to source-code and to derived similar architectural metrics using scatter plot, Pearson’s correlation coefficient and significance tests. The observations contradict the common assumption that software quality attributes (aka non-functional requirements) are mostly determined at the architectural level and raise new issues for future works in this field.