Jens H. Jahnke

Reverse engineering: a roadmap

By the early 1990s the need for reengineering legacy systems was already acute, but recently the demand has increased significantly with the shift toward web-based user interfaces. The demand by all business sectors to adapt their information systems to the Web has created a tremendous need for methods, tools, and infrastructures to evolve and exploit existing applications efficiently and cost-effectively. Reverse engineering has been heralded as one of the most promising technologies to combat this legacy systems problem. This paper presents a roadmap for reverse engineering research for the first decade of the new millennium, building on the program comprehension theories of the 1980s and the reverse engineering technology of the 1990s.

Predicting maintainability with object-oriented metrics -an empirical comparison

A large number of metrics have been proposed formeasuring properties of object-oriented software such assize, inheritance, cohesion and coupling. We have beeninvestigating which of these object-oriented metrics canbe used as significant predictors for the maintainability ofsoftware. For this purpose, we have designed andconducted an empirical study based on historical datacollected from the maintenance history of a medium-sizedobject-oriented system. Unlike most related studies,indirect coupling has also been taken into account in ourwork in order to evaluate its impact. Our study uses themaintenance history of two software systems as evidencebase for linking software quality attributes to metricssuggested for object-oriented software. Our resultsindicate that size and import direct coupling metrics aresignificant predictors for measuring maintainability ofclasses while inheritance, cohesion, and indirect/exportcoupling measures are not.

Facilitating the programming of the smart home

The ongoing miniaturization and cost reduction in electronic hardware has created opportunity for equipping homes with inexpensive smart devices for controlling and automating various tasks in our daily lives. Networking technology and standards have an important role in driving this development. We discuss how technological progress in the areas of visual programming languages, component software, and connection-based programming can be applied to programming the smart home. As an example of an industrial prototype solution, we present microCommander, a visual tool for rapidly programming synergetic devices for the smart home.

Generic fuzzy reasoning nets as a basis for reverse engineering relational database applications

Object-oriented technology has become mature enough to satisfy many new requirements coming from areas like computer-aided design (CAD), computer-integrated manufacturing (CIM), or software engineering (SE). However, a competitive information management infrastructure often demands to merge data from CAD-, CIM-, or SE-systems with business data stored in a relational system. One approach for seamless integration of objectoriented and relational systems is to migrate from a relational to an objectoriented system. The first step in this migration process is reverse engineering of the legacy database. In this paper we propose a new graphical and executable language called Generic Fuzzy Reasoning Nets for modelling and applying reverse engineering knowledge. In particular, this language enables to define and analyse fuzzy knowledge which is usually all what is available when an existing database schema has to be reverse engineered into an object-oriented one. The analysis process is based on executing a fuzzy petri net which is parameterized with the fuzzy knowledge about a concrete database application.

Reverse engineering tools as media for imperfect knowledge

Reverse engineering is an imperfect process driven by imperfect knowledge. Most current reverse engineering tools do not adequately consider these inherent characteristics. They focus an representing precise, complete and consistent knowledge and work towards enforcing predefined structures on the processes. According to our experience, this design paradigm seriously limits human-centred reverse engineering tools. An altogether different approach is to directly support the statement and subsequent resolution of imperfections. Doing so requires the imperfect knowledge be represented and imperfect procedures accommodated for. We argue that effective tools need to act as a manipulable medium for imperfect knowledge and, based on our experiences with a prototype, elaborate requirements for such tools.

Using the Clinical Document Architecture as Open Data Exchange Format for Interfacing EMRs with Clinical Decision Support Systems

Clinical decision support systems (CDSS) can significantly increase the quality of care while decreasing cost and effort. They are difficult to develop and most existing systems are proprietary, tightly integrated with specific electronic medical record (EMR) systems, and expensive to own. EGADSS is an open-source CDSS that has been developed as a standalone, standards-based, re-usable component to make decision-support available for any EMR. In order to realize this vision, the EGADSS team has had to develop an open interface for medical data exchange, which maximizes interoperability, simplicity and standard-conformance. This paper reports on a solution to this challenge based on the HL7 clinical document architecture (CDA) and the electronic medical summary standard. CDA-based medical summaries are used to encapsulate virtual medical records about patients that serve the DSS component as temporary databases. We show how these temporary databases can be queried from within Arden syntax-based guidelines in a standard query language. Moreover, we show how the CDA can be used to communicate CDSS alerts and recommendations back to the EMR. We report on our evaluation with a prototype implementation and compare it with alternative approaches

The e-Hospice: beyond traditional boundaries of palliative care

The term palliative care refers to the care for patients with terminal conditions. Traditionally, much of this end-of-life care has been provided by hospices or acute care centres. As healthcare systems face aging patient demographics and struggle with the need to deliver quality services with fewer resources, we must find new approaches to healthcare delivery. Some of the more established areas of healthcare such as cardiac care or administration are rather advanced in terms of the application of information technologies such as clinical knowledge bases and computer-integrated service delivery models. In palliative care, partly due to its relatively recent emergence as a discipline, informatics has played only a minor role to date. In this paper, we argue that we can achieve cost reduction and increased quality of service by adopting network-enabled information systems (IS) and telematics to advance the boundaries of traditional palliative care towards the patient homes. This vision, called e-Hospice in this article, is not meant to replace but to augment the traditional brick and mortar hospices. We discuss our model of an e-Hospice along with the challenges and opportunities involved in realising it. Our experiences are based on our ongoing tight collaboration with a local hospice as well as our studies of prototype technology infrastructures we have developed in our laboratories. We present a concrete application scenario in this paper, along with a description of the underlying architecture and technologies that underlie the infrastructures developed.

Interactive migration of legacy databases to net-centric technologies

Due to the rapid growth of e-commerce (and other Internet-related technologies), many companies want to migrate their information systems to the net-centric environment. We are proposing a toolkit (Varlet/Babel) that helps the user to achieve this goal. This is accomplished in two stages. In the first stage, a database schema is obtained and refined, then an XML description for the database schema is generated and used to wrap access to the information system. In this paper, we focus on the second stage and describe the methods that are used to create a mapping between the generated schema and a standard (interchange) schema and to make a second wrapper around the information system.

Ontology-based information integration in health care: a focus on palliative care

Electronic information integration has the potential to rationalise and improve business processes in many public and private sectors. A key challenge in any information integration task is to resolve the heterogeneity among the semantic terminologies used in the various information sources to be integrated. This paper describes how ontologies can be developed to achieve this resolution of semantic heterogeneity. We discuss a case study with a particular focus in the application domain of health care, namely palliative care. We begin by describing the methodology upon which our ontology is designed. The methodology description includes details on the conceptual framework and formalization of the framework to design our ontology. We then illustrate proposed implementation of the ontology in two ways. First, we show its use in creating patient specific clinical practice guidelines. Second, we describe the use of the ontology in palliative care systems by showing how it can assist in database design, decision support, and act as knowledge management tool for facilitating information sharing.

Supporting iterations in exploratory database reengineering processes

Key technologies like the World Wide Web, object-orientation, and distributed computing enable new applications, e.g., in the area of electronic commerce, management of information systems, and decision support systems. Today, many companies face the problem that they have to reengineer pre-existing information systems to take advantage of these technologies. Various computer-aided reengineering tools have been developed to reduce the complexity of the reengineering task. A major limitation of current approaches, however, is that they impose a strictly phase-oriented, waterfall-type reengineering process, with little support for iterations. Still, such iterations often occur in real-world examples, e.g., when additional knowledge about the legacy system becomes available or when the legacy system is modified during an ongoing migration process. In this paper, we present an approach to incremental consistency management that allows to overcome this limitation in the domain of database systems by integrating reverse and forward engineering activities in an intertwined process. The described mechanism is based on a formalization of conceptual schema translation and redesign transformations by graph rewriting rules and has been implemented and evaluated with the Varlet database reengineering environment.