Marko Bošković

Modeling and validation of business process families

Process modeling is an expensive task that needs to encompass requirements of different stakeholders, assure compliance with different standards, and enable the flexible adaptivity to newly emerging requirements in todays dynamic global market. Identifying reusability of process models is a promising direction towards reducing the costs of process modeling. Recent research has offered several solutions. Such solutions promote effective and formally sound methods for variability modeling and configuration management. However, ensuring behavioral validity of reused process models with respect to the original process models (often referred to as reference process models) is still an open research challenge. To address this challenge, in this paper, we propose the notion of business process families by building upon the well-known software engineering discipline-software product line engineering. Business process families comprise (i) a variability modeling perspective, (ii) a process model template (or reference model), and (iii) mappings between (i) and (ii). For business process families, we propose a correct validation algorithm ensuring that each member of a business process family adheres to the core intended behavior that is specified in the process model template. The proposed validation approach is based on the use of Description Logics, variability is represented by using the well-known Feature Models and behavior of process models is considered in terms of control flow patterns. The paper also reports on the experience gained in two external trial cases and results obtained by measuring the tractability of the implementation of the proposed validation approach.

Trustworthy software systems: a discussion of basic concepts and terminology

Basic concepts and terminology for trustworthy software systems are discussed. Our discussion of definitions for terms in the domain of trustworthy software systems is based on former achievements in dependable, trustworthy and survivable systems. We base our discussion on the established literature and on approved standards. These concepts are discussed in the context of our graduate school TrustSoft on trustworthy software systems. In TrustSoft, we consider trustworthiness of software systems as determined by correctness, safety, quality of service (performance, reliability, availability), security, and privacy. Particular means to achieve trustworthiness of component-based software systems - as investigated in TrustSoft - are formal verification, quality prediction and certification; complemented by fault diagnosis and fault tolerance for increased robustness.

A quality aggregation model for service-oriented software product lines based on variability and composition patterns

Quality evaluation is a challenging task in monolithic software systems. It is even more complex when it comes to Service-Oriented Software Product Lines (SOSPL), as it needs to analyze the attributes of a family of SOA systems. In SOSPL, variability can be planned and managed at the architectural level to develop a software product with the same set of functionalities but different degrees of non-functional quality attribute satisfaction. Therefore, architectural quality evaluation becomes crucial due to the fact that it allows for the examination of whether or not the final product satisfies and guarantees all the ranges of quality requirements within the envisioned scope. This paper addresses the open research problem of aggregating QoS attribute ranges with respect to architectural variability. Previous solutions for quality aggregation do not consider architectural variability for composite services. Our approach introduces variability patterns that can possibly occur at the architectural level of an SOSPL. We propose an aggregation model for QoS computation which takes both variability and composition patterns into account.

Validation of families of business processes

A Software Product Line (SPL) is a set of programs that are developed as a whole and share a set of common features. Product lines variability is typically specified using problem space models (i.e., feature models), solution space models that specify the realization of functionality and mapping models that link problem and solution space artifacts. In this paper, we consider this concept in the scope of families of business processes, whose specificity is that the solution space is defined with business process models. Solution space models are typically specified as model templates, and thus in the rest of the paper we will refer to business process model templates. While the previous research tackled the concepts of families of business processes, there have been very limited research on their validation.

AUTOMATED STAGED CONFIGURATION WITH SEMANTIC WEB TECHNOLOGIES

Since the introduction in the early nineties, feature models receive a great deal of attention in industry and academia. Industrial success stories in applying feature models for modeling software product lines, and using them for configuring software-intensive systems motivate academia to discover ways to integrate different feature dependencies into the feature model, and automate verified feature configuration. In this paper we demonstrate how ontologies and Semantic Web technologies facilitate seamless integration of required external services and deployment platform capabilities into the feature model. Furthermore, we also contribute with an algorithm for automating staged configuration using Semantic Web reasoners to discover unfeasible features of the feature model.

Aspect-oriented feature models

Software Product Lines (SPLs) have emerged as a prominent approach for software reuse. SPLs are sets of software systems called families that are usually developed as a whole and share many common features. Feature models are most typically used as a means for capturing commonality and managing variability of the family. A particular product from the family is configured by selecting the desired features of that product. Typically, feature models are considered monolithic entities that do not support modularization well. As industrial feature models tend to be large, their modularization has become an important research topic lately. However, existing modularization approaches do not support modularization of crosscutting concerns. In this paper, we introduce Aspect-oriented Feature Models (AoFM) and argue that using aspect-oriented techniques improves the manageability and reduces the maintainability effort of feature models. Particularly, we advocate an asymmetric approach that allows for the modularization of basic and crosscutting concerns in feature models.

Development and configuration of service-oriented systems families

Software Product Lines (SPLs) are families of software systems which share a common sets of feature and are developed through common set of core assets in order to promotes software reusability, mass customization, reducing cost, time-to-market and improving the quality of the product. SPLs are sets (i.e., families) of software applications developed as a whole for a specific business domain. Particular applications are derived from software families by selecting the desired features through configuration process. Traditionally, SPLs are implemented with systematically developed components, shared by members of the SPLs and reused every time a new application is derived. In this paper, we propose an approach to the development and configuration of Service-Oriented SPLs in which services are used as reusable assets and building blocks of implementation. Our proposed approach also suggests prioritization of family features according to stakeholders non-functional requirements (NFRs) and preferences. Priorities of NFRs are used to filter the most important features of the family, which is performed by Stratified Analytic Hierarchical Process (S-AHP). The priorities also are used further for the selection of appropriate services implementation for business processes realizing features. We apply Mixed Integer Linear Programming to find the optimal service selection within the constraints boundaries specified by stakeholders.

Model Driven Performance Measurement and Assessment with MoDePeMART

Software performance is one of important software Quality of Service attributes. For this reason, several approaches integrate performance prediction in Model Driven Engineering(MDE). However, MDE still lacks a systematic approach for performance measurement and metrics assessment. This paper presents MoDePeMART, an approach for Model Driven Performance Measurement and Assessment with Relational Traces. The approach suggests declarative specification of performance metrics in a domain specific language and usage of relational databases for storage and metric computation. The approach is evaluated with the implementation of a UML Profile for UML Class and State diagrams and transformations from profile to a commercial relational database management system.

Validation of user intentions in process models

Goal models and business process models are complementary artifacts for capturing the requirements and their execution flow in software engineering. Usually, goal models serve as input for designing business process models, and it requires mappings between both types of models. Due to the large number of possible configurations of elements from both goal models and business process models, developers struggle with the challenge of maintaining consistent configurations of both models and their mappings. Managing these mappings manually is error-prone. In our work, we propose an automated solution that relies on Description Logics and automated reasoners for validating mappings that describe the realization of goals by activities in business process models. The results are the identification of two inconsistency patterns --- strong inconsistency and potential inconsistency, and the development of the corresponding algorithms for detecting inconsistencies.

Model-Driven Performance Evaluation for Service Engineering

Service engineering and service-oriented architecture as an integration and platform technology is a recent approach to software systems integration. Software quality aspects such as performance are of central importance for the integration of heterogeneous, distributed service-based systems. Empirical performance evaluation is a process of measuring and calculating performance metrics of the implemented software. We present an approach for the empirical, model-based performance evaluation of services and service compositions in the context of model-driven service engineering. Temporal databases theory is utilised for the empirical performance evaluation of model-driven developed service systems.