Eila Niemelä

Survey of reliability and availability prediction methods from the viewpoint of software architecture

Many future software systems will be distributed across a network, extensively providing different kinds of services for their users. These systems must be highly reliable and provide services when required. Reliability and availability must be engineered into software from the onset of its development, and potential problems must be detected in the early stages, when it is easier and less expensive to implement modifications. The software architecture design phase is the first stage of software development in which it is possible to evaluate how well the quality requirements are being met. For this reason, a method is needed for analyzing software architecture with respect to reliability and availability. In this paper, we define a framework for comparing reliability and availability analysis methods from the viewpoint of software architecture. Our contribution is the comparison of the existing analysis methods and techniques that can be used for reliability and availability prediction at the architectural level. The objective is to discover which methods are suitable for the reliability and availability prediction of today’s complex systems, what are the shortcomings of the methods, and which research activities need to be conducted in order to overcome these identified shortcomings. The comparison reveals that none of the existing methods entirely fulfill the requirements that are defined in the framework. The comparison framework also defines the characteristics required of new reliability and availability analysis methods. Additionally, the framework is a valuable tool for selecting the best suitable method for architecture analysis. Furthermore, the framework can be extended and used for other evaluation methods as well.

Capturing quality requirements of product family architecture

Software quality is one of the major issues with software intensive systems. Moreover, quality is a critical success factor in software product families exploiting shared architecture and common components in a set of products. Our contribution is the QRF (Quality Requirements of a software Family) method, which explicitly focuses on how quality requirements have to be defined, represented and transformed to architectural models. The method has been applied to two experiments; one in a laboratory environment and the other in industry. The use of the QRF method is exemplified by the Distribution Service Platform (DiSeP), the laboratory experiment. The lessons learned are also based on our experiences of applying the method in industrial settings.

Component documentation¿a key issue in software product lines

Abstract Product lines embody a strategic reuse of both intellectual effort and existing artefacts, such as software architectures and components. Third-party components are increasingly being used in product line based software engineering, in which case the integration is controlled by the product line architecture. However, the software integrators have difficulties in finding out the capabilities of components, because components are not documented in a standard way. Documentation is often the only way of assessing the applicability, credibility and quality of a third-party component. Our contribution is a standard documentation pattern for software components. The pattern provides guidelines and structure for component documentation and ensures the quality of documentation. The pattern has been validated by applying and analysing it in practice.

A Taxonomy of Information Security for Service-Centric Systems

Pervasive communications and the rapid expansion of Internet trigger a myriad of concerns about trust and information security. Moreover, composing software from components and services, originating from diverse sources, without a thorough quality assurance practices may expose serious weaknesses that open up the systems for malicious attacks and misuse. In order to guarantee the security of the systems we need a uniform understanding about what security is and how to measure it. This paper introduces a taxonomy of information security, intended for the use of software architects of service centric systems. The security taxonomy extends our quality oriented architecting environment (QoAE) - an integrated tool environment for defining quality ontologies, describing the quality properties of service architectures, and analyzing quality requirement satisfaction at the level of proposed architecture.

Viewpoints of DSP software and service architectures

The software architecture of a future mobile telecommunication system consists of three main parts: system infrastructure services, middleware services and application services. Infrastructure services provide access technologies and networking services for the middleware services that again provide richer capabilities for wireless applications through mobile Internet. Architecture describes the organization of software systems, components, their internal relationships and connections to the environment. Reusing architectural structures benefits companies, because the architecture is a pivotal part of any system, and a costly one to construct. Architecture is documented and reused through architectural views that describe identified stakeholders and concerns, e.g. the purpose of a system, and the feasibility of constructing, deploying, evolving and maintaining it. Views conform to special viewpoints defined for the domain. This paper describes the viewpoints selected for developing the architecture of middleware services and digital signal processing software and provides a general framework for comparing viewpoints. Comparison and analysis of the defined viewpoints show that domain and system size are the dominant issues to be considered when architectural viewpoints are being selected.

Practical Evaluation of Software Product Family Architectures

Faster time to market and decreased development and maintenance costs are goals most companies are trying to reach. Product family engineering (PFE) provides a means of achieving these goals. Product family architecture (PFA) is the key issue in family engineering. However, companies have to decide how to adopt PFE and how to develop their software PFA. This paper introduces the basic issues essential to PFA development, explores three different approaches to applying PFAs in industrial settings, and, finally, presents the evaluation results through an evaluation model of software product families.

A Survey on Semantic Web Services and a Case Study

Semantic Web services integrate the meaningful content of the semantic Web with the business logic of Web services and thus enable industries and individuals to build, access, deploy and execute services and transactions independently over Internet. This paper surveys semantic Web services from the viewpoints of Web service architectures, service engineering, service description languages, Web service building tools, and also presents a case study

Original software component manufacturing: survey of the State-of-the-Practice

This paper analyses the state-of-the-practice of software components produced in strategic partnerships. We call this kind of business original software component manufacturing (OCM), referring to the concept of original equipment manufacturing (OEM) that is well known in other industries. The analysis is mostly based on information acquired from Internet in Fall 2000, dealing with OCM supplier; brokering and buyer companies. Based on the analysis, the context of OCM is outlined and a suggestion made for further R&D activities.

Strategies of product family architecture development

Product family engineering (PFE) is successfully applied in different kinds of software intensive systems. As there are several ways to apply PFE, selecting an appropriate approach is a complex task. This paper introduces six ways to set the goal of PFE and eight strategies to achieve the goal. It also introduces steps how to evaluate which strategy provides the best fit for a company. The criteria for selecting a strategy have been derived from seventeen case studies, including nineteen product families, in the various contexts provided by small, medium size and large companies.

Feature modelling of component-based embedded software

The electronic and automation industries develop and maintain software embedded in computer controlled products. Higher software productivity can be achieved by a systematic software engineering process and an environment that supports automatic software mass customisation. Existing methods are too narrow and commercial tools are often too closed to be suited for component based software tailoring. Integrating feature and object based models and providing a distributed environment based on commercial tools feature models of embedded software are utilized in reuse oriented product development, maintenance and sales. Reuse of product knowledge is based on layered feature models. Configuration data for product variations is automatically derived and mapped to software design and implementation components and assemblies.