Nikola Milanovic

Analytical availability assessment of IT services

The often neglected problem in the service availability analysis is mapping between ICT-infrastructure and service-level availability. We present an approach which allows to map ICT-infrastructure elements to services, and to analytically assess steady-state, interval and user-perceived service availability, based on failure distributions of ICT-elements that implement a composite service. In case that full topology or all failure distributions of ICT-infrastructure elements are unknown, we provide means to estimate upper and lower availability bounds.

Automatic Generation of Service Availability Models

In the world where on-demand and trustworthy service delivery is one of the main preconditions for successful business, service and business process availability is of the paramount importance and cannot be compromised. For that reason service availability is coming into central focus of the IT operations and management research and practice. Still, our understanding of service and process availability is mostly empirical and at best, sketchy. Services are assessed using a mixture of qualitative, quantitative, and analytical methods, with results of varying quality. We introduce a systematic model-based methodology and a tool for service and business process availability assessment. The main advantage of the proposed method is the ability to automatically generate availability models, based on the service/process description and technical infrastructure it is executing on. Therefore, service level agreements can be tested/simulated or return on investment calculation can be performed, without the need for costly experiments and/or actual investments.

Model&Metamodel, Metadata and Document Repository for Software and Data Integration

Model-based software engineering (MBSE) projects require and generate numerous artifacts. While MBSE methodology and design tools have reached certain maturity level, the issue of artifact persistence and management has been somewhat left in the background. We present design and implementation of the repository that supports storing and managing of artifacts such as metamodels, models, constraints, metadata, specifications, transformation rules, code, templates, configuration or documentation, and their metadata.

Modeling Business Process Availability

In the world where on-demand and trustworthy service delivery is one of the main preconditions for successful business, availability of the services and business processes is of the paramount importance and cannot be compromised. We present a framework for modeling business process availability that takes into account services, the underlying ICT-infrastructure and people. Based on a fault model, we develop the methodology to map dependencies between ICT-components, services and business processes. The mapping enables us to model and analytically assess steady-state, interval and user perceived availability at all levels, up to the level of the business process.

Metamodeling Foundation for Software and Data Integration

We propose a model-based methodology for integration of heterogeneous distributed systems, based on the multi-level modeling abstractions, automated conflict analysis and connector code generation. The focus in this paper is on the metamodeling foundation necessary for this process, and consequently we introduce computation independent, platform specific, platform independent and semantic metamodels, which generate a set of domain specific languages used to describe software and data integration scenarios.

Executable Domain Specific Language for Message-Based System Integration

Heterogeneous IT-systems rarely rely on a common data format and structure, so in order to integrate them, the corresponding data/message transformations must be developed. Transformations may also be required by the business logic. We present a platform-independent approach for message transformation specification, in form of a system integration DSL, and discuss approaches for making it executable.

Model-Based Interoperability of Heterogeneous Information Systems: An Industrial Case Study

Integration of heterogeneous and distributed IT-systems is one of the major cost-driving factors in the software industry. We introduce a model-based approach for information system integration and demonstrate it on the industrial case-study of data integration between the Oracle database management system and the SAP R/3 enterprise resource planning system. Particular focus is on multi-level modeling abstractions, integration conflict analysis (automatic data model matching), semantic reasoning, code generation and tool support.

Modeling and Analyzing Non-Functional Properties to Support Software Integration

Software integration is one of the major needs as well as cost driving factors in the software industry today. Still, very few established methodologies exist, especially those addressing integration with respect to non-functional properties. Industry studies show that disregarded and hidden non-functional incompatibilities between systems and their interfaces are the constant source of errors and costly workarounds. We introduce a model-based process that allows dynamic definition of non-functional properties in the context of software integration, present a NFP taxonomy, and propose a method for formal analysis of interface incompatibilities with respect to these properties.

(Meta-)Models, Tools and Infrastructures for Business Application Integration

In the context of the Berlin Brandenburg Business Process Integration and Evolution framework BIZYCLE, we are using modeling and metamodeling strategies in order to achieve a platform for the (semi) automatic integration of software components. Our general methodology is based on the principles of the MDA paradigm, distinguishing between platform specific (PSM), platform independent (PIM) and computation independent (CIM) models, and on the general philosophy of solving integration problems on higher levels of abstraction. The basic models and metamodels on CIM, PIM and PSM level, forming the pre-requisite for our further project work, are examined in this article.

Model-Based Software and Data Integration

This book includes selected papers of the First International Workshop on Model-Based Software and Data Integration 2008, held in Berlin, Germany, in April 2008 as a part of the Berlin Software Integration Week 2008. The 9 revised full papers presented together with 3 invited lectures were carefully reviewed and selected from numerous submissions. The papers are organized in topical sections on data integration, software architectures, services and migration, as well as on model-based and semantic approaches.