Iris Reinhartz-Berger

Extending the Adaptability of Reference Models

Reference models are an important aid for business process modeling and design. Their aim is to capture domain knowledge and assist in the design of enterprise-specific business processes. The application of reference models for process design requires guidance in reusing these models and flexibility in adapting them to specific enterprises. One popular modeling language for specifying reference models is event-driven process chain (EPC), which has been extended to express configurable reference models, i.e., configurable EPC (C-EPC). These models provide explicit reuse guidance but allow a limited level of flexibility following a reuse by configuration approach. To increase the level of adaptability of reference models, in this paper, we propose to utilize the application-based domain modeling (ADOM) approach to specify and apply reference models by using EPC. ADOM supports the enforcement of reference model constraints while allowing high levels of flexibility, adaptability, and variability in the business processes of particular enterprises. This paper presents the syntax and semantics of the proposed approach, called ADOM-EPC, and its specialization and configuration capabilities. ADOM-EPC is evaluated by comparing it to C-EPC, a leading approach for reference modeling and reuse, in terms of expressiveness and comprehensibility. Although the expressiveness of ADOM-EPC, i.e., its set of specified reuse operations, exceeds that of C-EPC, the understandability of the two types of reference models is similar.

Utilizing domain models for application design and validation

Domain analysis enables identifying families of applications and capturing their terminology in order to assist and guide system developers to design valid applications in the domain. One major way of carrying out the domain analysis is modeling. Several studies suggest using metamodeling techniques, feature-oriented approaches, or architectural-based methods for modeling domains and specifying applications in those domains. However, these methods mainly focus on representing the domain knowledge, providing insufficient guidelines (if any) for creating application models that satisfy the domain rules and constraints. In particular, validation of the application models which include application-specific knowledge is insufficiently dealt. In order to fill these lacks, we propose a general approach, called Application-based DOmain Modeling (ADOM), which enables specifying domains and applications similarly, (re)using domain knowledge in application models, and validating the application models against the relevant domain models. In this paper we present the ADOM approach, demonstrating its application to UML 2.0 class and sequence diagrams.

A semantic approach to approximate service retrieval

Web service discovery is one of the main applications of semantic Web services, which extend standard Web services with semantic annotations. Current discovery solutions were developed in the context of automatic service composition. Thus, the “client” of the discovery procedure is an automated computer program rather than a human, with little, if any, tolerance to inexact results. However, in the real world, services which might be semantically distanced from each other are glued together using manual coding. In this article, we propose a new retrieval model for semantic Web services, with the objective of simplifying service discovery for human users. The model relies on simple and extensible keyword-based query language and enables efficient retrieval of approximate results, including approximate service compositions. Since representing all possible compositions and all approximate concept references can result in an exponentially-sized index, we investigate clustering methods to provide a scalable mechanism for service indexing. Results of experiments, designed to evaluate our indexing and query methods, show that satisfactory approximate search is feasible with efficient processing time.

OPM vs. UML—Experimenting with Comprehension and Construction of Web Application Models

Object-Process Methodology (OPM), which is a holistic approach to modeling and evolving systems, views objects and processes as two equally important entities that describe the systems structure and behavior in a single model. Unified Modeling Language (UML), which is the standard object-oriented modeling language for software systems, separates the system model into various aspects, each of which is represented in a different view (diagram type).The exponential growth of the Web and the progress of Internet-based architectures have set the stage for the proliferation of a variety of Web applications, which are classified as hybrids between hypermedia and information systems. Such applications require a modeling approach that is capable of clearly specifying aspects of their architecture, communication, and distributive nature. Since UML and OPM are two candidates for this task, this study has been designed to establish the level of comprehension and the quality of the constructed Web application models using each one of these two approaches.In the experiment we carried out, third year undergraduate information systems engineering students were asked to respond to comprehension and construction questions about two representative Web application models. The comprehension questions related to the systems structure, dynamics, and distribution aspects. The results suggest that OPM is better than UML in modeling the dynamics aspect of the Web applications. In specifying structure and distribution aspects, there were no significant differences. The results further suggest that the quality of the OPM models students built in the construction part was superior to that of the corresponding UML models.

Developing Complex Systems with Object-Process Methodology Using OPCAT

OPCAT – Object-Process CASE Tool – is an integrated systems engineering environment. It supports system lifecycle evolution using Object-Process Methodology (OPM). OPM integrates the object-oriented (structure) and process-oriented (behavior) paradigms into a single frame of reference through a combination of graphics and equivalent natural language. This short paper briefly describes OPM and demonstrates highlights of OPCAT and some of its capabilities.

Organisational reference models: supporting an adequate design of local business processes

Reference models, whose aim is to capture domain knowledge, can assist in the adequate design of enterprise specific business processes. In complex organisations, business processes can be locally designed by specific organisational units. However, in order to be adequate, these processes should meet the local needs while maintaining the organisational standards. For this purpose, we propose to create an organisational reference model that specifies the organisational standards, guides and constrains the different organisational units when designing their specialised local processes. We propose a reference modelling approach called application-based domain modelling (ADOM), which is capable of specifying guidelines and constraints as part of the reference model and validating a specific model against the reference model. The paper presents the principles of ADOM and in particular, its novel validation procedure. This procedure enables the organisation to ensure that the local processes are in compliance with the organisational standards, as specified in the reference model. We demonstrate the validation procedure on a purchase requisition reference model within a university and its application in two sub units: a library and an acquisition department.

Enhancing UML Models: A Domain Analysis Approach

UML has been largely adopted as a standard modeling language. The emergence of UML from different modeling languages that refer to various system aspects causes a wide variety of completeness and correctness problems in UML models. Several methods have been proposed for dealing with correctness issues, mainly providing internal consistency rules but ignoring correctness and completeness with respect to the system requirements and the domain constraints. In this article, we propose addressing both completeness and correctness problems of UML models by adopting a domain analysis approach called application-based domain modeling (ADOM). We present experimental results from our study which checks the quality of application models when utilizing ADOM on UML. The results advocate that the availability of the domain model helps achieve more complete models without reducing the comprehension of these models.

OPM/Web – Object-Process Methodology for Developing Web Applications

Web applications can be classified as hybrids between hypermedia and information systems. They have a relatively simple distributed architecture from the user viewpoint, but a complex dynamic architecture from the designer viewpoint. They need to respond to operation by an unlimited number of heterogeneously skilled users, address security and privacy concerns, access heterogeneous, up-to-date information sources, and exhibit dynamic behaviors that involve such processes as code transferring. Common system development methods can model some of these aspects, but none of them is sufficient to specify the large spectrum of Web application concepts and requirements. This paper introduces OPM/Web, an extension to the Object-Process Methodology (OPM) that satisfies the functional, structural and behavioral Web-based information system requirements. The main extensions of OPM/Web are adding properties of links to express requirements, such as those related to encryption; extending the zooming and unfolding facilities to increase modularity; cleanly separating declarations and instances of code to model code transferring; and adding global data integrity and control constraints to express dependence or temporal relations among (physically) separate modules. We present a case study that helps evaluate OPM/Web and compare it to an extension of the Unified Modeling Language (UML) for the Web application domain.

Towards automatization of domain modeling

A domain model, which captures the common knowledge and the possible variability allowed among applications in a domain, may assist in the creation of other valid applications in that domain. However, to create such domain models is not a trivial task: it requires expertise in the domain, reaching a very high level of abstraction, and providing flexible, yet formal, artifacts. In this paper an approach, called Semi-automated Domain Modeling (SDM), to create draft domain models from applications in those domains, is presented. SDM takes a repository of application models in a domain and matches, merges, and generalizes them into sound draft domain models that include the commonality and variability allowed in these domains. The similarity of the different elements is measured, with consideration of syntactic, semantic, and structural aspects. Unlike ontology and schema integration, these models capture both structural and behavioral aspects of the domain. Running SDM on small repositories of project management applications and scheduling systems, we found that the approach may provide reasonable draft domain models, whose comprehensibility, correctness, completeness, and consistency levels are satisfactory.

An empirical study of requirements model understanding: Use Case vs. Tropos models

Visual modelling languages are commonly used to support software requirements analysis and documentation. A variety of languages are available, based on different conceptual paradigms. They can be roughly divided into two main groups: goal-oriented approaches and scenario-based approaches. In the last ten years, numerous works developed case studies that illustrate the effectiveness and limitations of goal-oriented and scenario-based approaches. A few works even suggest coupling these approaches in order to capture requirements from different perspectives. However, experimental comparisons of these approaches have been rarely addressed. This paper presents the design and preliminary results of an empirical study that compares two state of the art requirements modelling methods: Use Cases, which is a scenario-based approach, and Tropos, which is a goal-oriented approach. The objective is to evaluate different levels of comprehension of requirements models expressed in both methods, as well as to estimate the time required to perform simple analysis tasks using both methods. Preliminary results show that Tropos models seem to be more comprehensible, although more time consuming, than Use Case models to novice requirements analysts.