Software reliability is one of the most important quality indices in software quality evaluation, with the development of software engineering and component reusing, reliability analysis based on software architecture has become a researching hotspot. Reliability estimation during architectural design. Reliability, an important dependability attribute, is defined as the probability. Software reliability is the probability of failurefree software operation for a specified period of time in a specified environment. We modify model of software reliability estimation so that to improve precision of estimating software architecture reliability. Architecturebased software reliability modeling department of. In this chapter we discussed reliability, scalability, and maintainability in detail. Drive reliability improvement by design, both qualitatively and quantitatively, while infusing design for reliability dfr activities with relevant. The architecture of a web server has a profound impact on its performance. Availability is a simple measure of the percentage of time that a service, product, infrastructure component, machine, device or resource remains operational under normal conditions. Perform a software reliability goal setting by defining systemlevel software reliability goals. Reliability, availability and serviceability ras is a set of three related attributes that must be considered when designing, manufacturing, purchasing or using a computer product or component.
At the same time, this paper proposed the simplified method of calculating software architecture reliability based on the state. Software reliability is also an important factor affecting system reliability. Reliability aware software architecture design has recently been gaining growing attention among software architects. What is reliability, availability and serviceability ras. Software reliability cmuece carnegie mellon university. Reliability, availability, and maintainability ram are three system attributes that are of tremendous interest to systems engineers, logisticians, and users. Reliasoft software applications provide a powerful range of solutions to facilitate a comprehensive set of reliability engineering modeling and analysis techniques. Software architecture and design for reliability predictability, by assefa d.
Performance and reliability analysis ofweb server software architectures. Software architecture modeling and reliability evaluation. Reliability, availability and serviceability ras, also known as reliability, availability, and. Reliability, availability and serviceability ras, also known as reliability, availability, and maintainability ram, is a computer hardware engineering term involving reliability engineering, high availability, and serviceability design. Software functional quality reflects how well it complies with or conforms to a given design, based on functional requirements or specifications. With monitoring in place, your team will be automatically alerted when kpis deviate from expected norms. It is often defined as the probability of a failurefree operation of a computer. Software reliability integration in the design phase. The performance and scalability perspective this perspective addresses two related quality properties for large information systems. This is a guide for the savvy manager who wants to capitalize on the wave of change that is occurring with web services, serviceoriented architecture, andmore recentlycloud computing. Software reliability is one of the key metrics for determining the quality of software. It differs from hardware reliability in that it reflects the design. Details on the acid property of durability for databases.
Reliability engineering software products reliasoft. Reliability prediction for componentbased software. Data science, mathematics, network administration, software architecture see more. Depending on how you configure your implementation, this can include incidentfailure reporting, failure analysis on returned parts, part tracking for serialized systems, root cause analysis, teambased problem resolution and tracking the completion of assigned actions. Software reliability an overview sciencedirect topics. In the world of software architecture there are many ilities you must take into consideration with every project. Architectural design decisions for achieving reliable software. Architecturebased approaches to software reliability prediction.
Systems are a class of software that provide foundational services and automation. To my knowledge, no research has been done where a hierarchical approach is taken to estimate heterogeneous architecture based software reliability. This page describes a scientific approach to predict the reliability of it systems with componentbased software architectures. Reliability, availability, and maintainability sebok. Xfracas is a highly configurable, webbased failure reporting, analysis and corrective action system fracas. As a result, there is a need for modeling approaches that are capable of considering the architecture of the software made out of components. Our contribution is an ontologybased reliability aware software architecture development approach, i.
Keywords reliability analysis, scenario based architectural evaluation, fmea, fault trees. When you architect a system to automatically add and remove resources in response to changes in demand, this not only increases reliability but also ensures that business success doesnt become a burden. There are probably a variety of reasons for this omission, including the additional cost and time. The term was first used by ibm to define specifications for their mainframes and originally applied only to hardware. An aircraft that can be flown for many hours a month without much downtime can be said to have a high operational availability. Architectural design decisions for achieving reliable. Redundant hardware components and intelligent software architecture deliver extreme performance while also providing high availability. A modeling of software architecture reliability request pdf.
Modeling and estimating software reliability during testing is useful in quantifying the quality and dependability of the developed software systems. Parameterized reliability prediction for componentbased software architectures. Quality attribute requirements such as those for performance, security, modifiability, reliability, and usability have a significant influence on the software architecture of a system. However, such measurements applied so late in the development process leave done little to improve the quality of the software system in a costeffective way. Owing to the low cost, high profit and disasterfree, the reliability oriented evolution method is proposed in this paper. These properties are important because, in large systems, they can cause more unexpected, complex, and expensive problems late in the system lifecycle than most of the other properties. In international conference on the quality of software architectures qosa, volume 6093 of lncs, pages 3651. The phrase was originally used by international business machines as a term to describe the robustness of their mainframe computers. Reliability means making systems work correctly, even when faults occur. This combination provides exceptional reliability, while also leveraging components in new ways that decrease the total cost of ownership of each system.
That attribute can also be described as the fitness for purpose of a piece of software or how it compares to competitors in the marketplace as a. Software design for reliability accendo reliability. Reliability, maintainability, and availability ram are three system attributes that are of great. Ontoarch reliabilityaware software architecture design. A basic approach to architecture is to separate work into components. Design for reliability is a collection of techniques that are used to modify the initial design of a system to improve its reliability. This paper tackles the issue by introducing an ontologybased approach, called ontoarch, which is characterized by. The term reliability refers to the ability of a computerrelated hardware or software component to consistently perform according to its specifications.
The 7 software ilities you need to know filed under architecture. Sarah results in a failure analysis report that can be utilized to identify architectural tactics for improving the reliability of the software architecture. Performance and reliability analysis ofweb server software. Reliability aware software architecture development has recently been gaining growing attention among software architects. In the context of software engineering, software quality refers to two related but distinct notions. Existing models either use a blackbox approach that is based on test data of the whole system or a whitebox approach that uses components reliabilities and intercomponent interactions. A hierarchical framework for estimating heterogeneous. Pdf reliability analysis of software architecture evolution. This chapter tackles the issue by proposing an ontologybased, reliability aware software architecture design and evaluation approach, called ontoarch, which incorporates quantitativ. Given the connection between components and architecture, it is natural to extend contracts to the level of architectural specifications, and worthwhile to develop specialised methods for the prediction of quality attributes for componentbased software architectures hamlet et al. Prioritizing them is necessary because the client will optimistically ask that you do all of them. Designtime reliability prediction for software systems. This paper introduces software architecture reliability estimation and some typical software reliability model based architecture.
Xfracas fracas software webbased failure reporting. The approach is illustrated using an industrial case for analyzing reliability of the software architecture of the next release of a digital tv. The ontoarch approach integrates software reliability engineering, quality driven. Reliability prediction for componentbased software architectures. The following are illustrative examples of system architecture. The ideas are illustrated using an industrial case for analyzing reliability of the software architecture for a digital tv. Incorporating reliability goals in software architectures is important for successful applications in large and safetycritical systems. Department of defense dod contractors do not fully exploit these techniques. Reliability, availability, and maintainability the mitre.
Augment and refine the model later in the acquisition cycle, with design and test data during those program phases. System architecture is the structural design of systems. The method improves the reliability of software architecture by analysis. Software architecture and design for reliability predictability assefa d.
Software architecture and design for reliability predictability. Use reliability prediction and modeling to assess the risk in meeting ram requirements early in the program when a hardware software architecture is formulated. It differs from hardware reliability in that it reflects the design perfection, rather than manufacturing perfection. Collectively, they affect economic lifecycle costs of a system and its utility. Software testing risk selfadaptive system software engineering software architecture. To my surprise, i have observed a common phenomenon in many financial firms large and small with various degrees of architecture maturity of confusing solution architecture with software architecture. Pdf software engineers and practitioners regard software architecture as an important artifact, providing the means to model the structure and. However, most of the existing software design mechanisms do not consider the architectural reliability the impact of software architecture on system reliability.
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