Quality factors for dynamic evolution in composition-based distributed applications

Abstract

Dynamic evolution is a phenomenon by which applications can be upgraded without shutdown and restart. This capability improves service levels while minimising the loss of business revenue and is particularly important for a variety of mission critical distributed applications running around the clock. While quality plays an important role in information systems and their development, little attention has been paid in the literature to quality in dynamic evolution. This paper proposes a set of quality factors for dynamic evolution suitable for composition-based (e.g. service-oriented and component-based) distributed application development using a multi-step process for their incremental development and evaluation. An initial set of factors was developed from the relevant literature. This set of factors was evaluated for their perceived importance and extended by a web survey of experienced practitioners and researchers. A review of twelve relevant development methodologies was then conducted to further extend the revised set. The proposed set of factors can provide guidance for practitioners and researchers in developing, managing and/or testing distributed applications which can benefit from dynamic evolution. To demonstrate a use of the quality factors, an assessment was performed on the twelve methodologies to evaluate their extent of support for the extended set of quality factors, with results summarising their strengths and areas for improvement to support dynamic evolution.