Henderik A. Proper

Aakash Ahmad, Madhushi Bandara, Mahdi Fahmideh et al.

The outbreak of the SARS-CoV-2 pandemic of the new COVID-19 disease (COVID-19 for short) demands empowering existing medical, economic, and social emergency backend systems with data analytics capabilities. An impediment in taking advantages of data analytics in these systems is the lack of a unified framework or reference model. Ontologies are highlighted as a promising solution to bridge this gap by providing a formal representation of COVID-19 concepts such as symptoms, infections rate, contact tracing, and drug modelling. Ontology-based solutions enable the integration of diverse data sources that leads to a better understanding of pandemic data, management of smart lockdowns by identifying pandemic hotspots, and knowledge-driven inference, reasoning, and recommendations to tackle surrounding issues.

Rik D. T. Janssen, Henderik A. Proper

In this paper a functionality taxonomy for document search engines is proposed. It can be used to assess the features of a search engine, to position search engines relative to each other, or to select which search engine 'fits' a certain situation. One is able to identify areas for improvement. During development, we were guided by the viewpoint of the user. We use the word `search engine' in the broadest sense possible, including library and web based (meta) search engines. The taxonomy distinguishes seven functionality areas: an indexing service, user profiling, query composition, query execution, result presentation, result refinement, and history keeping. Each of these relates and provides services to other functionality areas. It can be extended whenever necessary. To illustrate the validity of our taxonomy, it has been used for comparing various document search engines existing today (ACM Digital Library, PiCarta, Copernic, AltaVista, Google, and GuideBeam). It appears that the functionality aspects covered by our taxonomy can be used for describing these search engines.

Alistair P. Barros, Arthur H. M. ter Hofstede, Henderik A. Proper

The workflow concept, proliferated through the recently emergent computer supported cooperative work (CSCW) systems and workflow systems, advances information systems (IS) implementation models by incorporating aspects of collaboration and coordination in business processes. Under traditional implementation models, applications are partitioned into discrete units of functionality, with (typically) operational procedures used to describe how human and computerised actions of business processes combine to deliver business services. In this paper, a number of essential modelling concepts and features for business transaction workflows are developed.

Alistair P. Barros, Arthur H. M. ter Hofstede, Henderik A. Proper et al.

By incorporating aspects of coordination and collaboration, workflow implementations of information systems require a sound conceptualisation of \EM{business processing} semantics. Traditionally, the success of conceptual modelling techniques has depended largely on the adequacy of conceptualisation, expressive power, comprehensibility and formal foundation. An equally important requirement, particularly with the increased conceptualisation of business aspects, is \EM{business suitability}. In this paper, the focus is on the business suitability of workflow modelling for a commonly encountered class of (operational) business processing, e.g. those of insurance claims, bank loans and land conveyancing. A general assessment is first conducted on some \EM{integrated} techniques characterising well-known paradigms - structured process modelling, object-oriented modelling, behavioural process modelling and business-oriented modelling. Through this, an insight into business suitability within the broader perspective of technique adequacy, is gained. A specific business suitability diagnosis then follows using a particular characterisation of business processing, i.e.\ one where the intuitive semantics and inter-relationship of business services and business processes are nuanced. As a result, five business suitability principles are elicited. These are proposed for a more detailed understanding and (synthetic) development of workflow modelling techniques. Accordingly, further insight into workflow specification languages and workflow globalisation in open distributed architectures may also be gained.

H. A. Proper

Effective information disclosure in the context of databases with a large conceptual schema is known to be a non-trivial problem. In particular the formulation of ad-hoc queries is a major problem in such contexts. Existing approaches for tackling this problem include graphical query interfaces, query by navigation, query by construction, and point to point queries. In this report we propose an adoption of the query by navigation mechanism that is especially geared towards the InfoAssistant product. Query by navigation is based on ideas from the information retrieval world, in particular on the stratified hypermedia architecture. When using our approach to the formulations of queries, a user will first formulate a number of simple queries corresponding to linear paths through the information structure. The formulation of the linear paths is the result of the {\em explorative phase} of the query formulation. Once users have specified a number of these linear paths, they may combine them to form more complex queries. Examples of such combinations are: concatenation, union, intersection and selection. This last process is referred to as {\em query by construction}, and is the {\em constructive phase} of the query formulation process.

H. A. Proper

Most present day organisations make use of some automated information system. This usually means that a large body of vital corporate information is stored in these information systems. As a result, an essential function of information systems should be the support of disclosure of this information. We purposely use the term {\em information disclosure} in this context. When using the term information disclosure we envision a computer supported mechanism that allows for an easy and intuitive formulation of queries in a language that is as close to the user's perception of the universe of discourse as possible. From this point of view, it is only obvious that we do not consider a simple query mechanism where users have to enter complex queries manually and look up what information is stored in a set of relational tables. Without a set of adequate information disclosure avenues an information system becomes worthless since there is no use in storing information that will never be retrieved.

P. D. Bruza, H. A. Proper

We are surrounded by an ever increasing amount of data that is stored in a variety of databases. In this article we will use a very liberal definition of \EM{database}. Basically any collection of data can be regarded as a database, ranging from the files in a directory on a disk, to ftp and web servers, through to relational or object-oriented databases. The sole reason for storing data in databases is that there is an anticipated need for the stored data at some time in the future. This means that providing smooth access paths by which stored information can be retrieved is at least as important as ensuring integrity of the stored information. In practice, however, providing users with adequate avenues by which to access stored information has received far less attention.

T. A. Barrett, H. A. Proper

Many of today's applications have an, almost tangible, monolithic nature. They are built as 'islands', purporting to be self contained, offering little or nothing in the way of integration with other applications. In the past, being large and self-contained may have eliminated the need to interact with other solutions to some extent. However, in the business environments of today the interaction with other applications becomes paramount. As a result of this, many ad-hoc point-to-point integration solutions have been built between different applications. This has already led to an 'application spaghetti' at many of our customer sites. Many of today's applications are poorly structured, which makes their responsiveness to business change sluggish. The application spaghetti with its plethora of point-to-point interfaces further inhibits the responsiveness to change.

H. A. Proper

This document has emerged out of Origin's past experiences with architecture-driven application development (AD2), and the need to further formalise and consolidate these experiences.

H. A. Proper, Th. P. van der Weide

In this article we focus on evolving information systems. First a delimitation of the concept of evolution is provided, resulting in a first attempt to a general theory for such evolutions. The theory makes a distinction between the underlying information structure at the conceptual level, its evolution on the one hand, and the description and semantics of operations on the information structure and its population on the other hand. Main issues within this theory are object typing, type relatedness and identification of objects. In terms of these concepts, we propose some axioms on the well-formedness of evolution. In this general theory, the underlying data model is a parameter, making the theory applicable for a wide range of modelling techniques, including object-role modelling and object oriented techniques.

Henderik A. Proper

Modeling of work systems occurs for all sorts of reasons. Requirements need to be expressed. A pre-existing situation may need to be charted and analyzed. Early design decisions may be captured using architecture principles. Detailed design may be worked out. We all regard these activities as essentially being forms of modeling. In the work systems modeling library, we consider work system engineering from a modeling perspective. In the field of work system engineering, a whole plethora of modeling methods is available to system engineers and architects. Each of these methods can be used to model some (aspects) of a domain related to an existing and/or a planned work system. The aspects may refer to requirements, architecture, design, processing, data, etc, etc. In other words, these methodes are essentially all intended to model different aspects of work systems and/or their context. The aim of the work systems modeling library (WSML) is to bring together methodical knowledge concerning the modeling of work systems.

R. D. T. Janssen, H. A. Proper, H. Bosma et al.

Today, there are millions of professionals worldwide acting as a designer, architect or engineer in the design, realization, and implementation of information systems. At this moment there is no well established and clearly identified body of knowledge that defines their profession in a "standard" way. In this article, we present the idea of developing an architecture method library. Such a library could play a pivotal role to further professionalize the field. The library contains project experiences, reference architectures, literature, proven methods, tools, etc. Access mechanisms allow the professional to use this body of knowledge. By giving it an open nature, it can be filled by professionals from different fields. Feedback mechanisms are possible to improve the contents of the library, for example by giving feedback on the method components in the library.