Quality-based bottom-up design of reference architecture applied to Healthcare Integrated Information Systems

Abstract

Software Product Line (SPL) is a set of softwareintensive systems, sharing a common, managed set of features that satisfy the specific needs of a particular market segment or domain. Reference Architecture (RA) is the main asset shared by all SPL products; it covers commonality and variability of the SPL family of products or systems and it is used as a template to produce new products. We propose a semi-automatic bottom-up refactoring process to build RA considering the logic view (static aspects) of architectures of existing products in a domain, represented by a connected graph or valid architectural configuration. A candidate architecture (CA) is obtained automatically and manually completed by introducing new variants to satisfy quality properties. RA is finally built by grouping into variation points CA variants accomplishing similar tasks. We consider functional and non-functional variability modeling of components and connectors. The quality properties to be satisfied are specified by the ISO/IEC 25010 quality model, using scenarios of available architectural solutions for each quality property that can be traced to the original component requiring it; our approach combines quality standards with goaloriented techniques to consider non-functional variability, which is still an open research issue in SPL. The complete RA design process is applied to the domain of Integrated Healthcare Information Systems.Keywords-software product line, reference architecture, bottom-up design, non-functional requirements, quality model.

Ontological approach to derive product configurations from a Software Product Line Reference Architecture

“…Our RA has been constructed in the Domain Engineering lifecycle [4] by a bottom-up process for the HIS domain, as it was mentioned above, considering three existing open-source products on the market. The representation of RA by a graph was used to derive automatically a first SPL candidate architecture after a similarity analysis of the architectural configurations of the existing products [12] [13]. Knowledge about NFR related to FR is specified by a standard quality model [15], to facilitate common understanding of software product quality terminology.…”

“…HIS are complex information systems, generally located in different and distant institutions and with mandatory NFR requirements, such as interoperability, availability and security. They are supported by a hybrid event-based Client-server/Layers architectural style [3] [13], used in distributed Web-based systems. HIS must facilitate transparent sharing of different kinds of medical information, such as EHR, offering also telemedicine services that can be performed on-line at remote locations, with wide information technology support.…”

“…To cope with this problem, many adaptations of features models can be found in the literature to consider also NFR [7] [25]. In our approach, FS are derived directly by instantiating RA, which has been constructed by a bottomup (extractive) semiautomatic process [12] [13], by refactoring architectures of existing products on the market. The bottom-up approach is claimed to be faster, less expansive, and more practical for industrial usage than classic SPL top-down approaches; however their limitation is that the number of existing products can be small [4].…”

“…The bottom-up approach is claimed to be faster, less expansive, and more practical for industrial usage than classic SPL top-down approaches; however their limitation is that the number of existing products can be small [4]. In our case, domain knowledge has been captured from the available documentation on three widely used existing products and it is imbedded into RA, which has been built considering explicitly quality properties related to FR, capturing also the overall domain quality [12] [13]. However, if our initial baseline or candidate architecture obtained automatically from the union of the architectural configurations of the existing products considered, is found limited due to the bottom-up construction, it could be extended with new components, by studying future products that can be built for the SPL.…”

“…An ontology is used in our approach to check the validity of deriving connected, consistent and working product configurations directly from the RA configuration, without involving feature models. Our RA, called HIS-RA, has been constructed for the Healthcare Integrated Information Systems (HIS) domain [13] [19]. The knowledge on HIS quality properties is imbedded into HIS-RA by construction.…”