When designing and developing software systems, there are several challenges that have to be addressed such as complexity, change management and system integrity. Trends in development processes, programming languages and software design are constantly changing. New programming paradigms have succeeded each other while the software systems have grown larger and more difficult to maintain. Component-oriented thinking provides the opportunity to re-use pre-fabricated parts to assemble software systems from tested building blocks, facilitating a rapid and consistent software development process. A component-oriented approach, however, affects both the life cycle and the development process of a software system. Therefore, a new way of viewing the life cycle as well as the development process for component-based software systems is presented in this thesis.

A key issue when using a component-oriented approach is to consider both behavioral and static aspects of a software system. Furthermore, we need to be able to analyze the architecture of the enterprise as well as the software system architecture to deliver business value with information systems. System interdependencies will be placed in the foreground when integrating technical and organizational aspects of the information system. We therefore need a modeling technique suitable for focusing on semantic aspects rather than implementation-dependent issues. A suitable modeling technique is the Enterprise Modeling approach.

This thesis will present a component-oriented approach to software system architectures using the Enterprise Modeling approach.

Component based software represents one of the new trends in the software development community. Although many years have passed since the concept of software components was first presented, it has not been a feasible approach until today. This is because of the added complexity which is a result of software component interconnectivity and multiplicity of life cycles in component based software systems.Ê To resolve the increased complexity, component based software needs a new approach in dealing with the development process as well as a new way of modeling the software.



This thesis presents a step towards a new approach to the development process and the life cycle of component based software. Furthermore, empowerment of existing modeling techniques have been initiated through the incorporation of component based thinking in the modeling techniques presented in this thesis. Combining the Enterprise modeling technique with UML, results in a more powerful and comprehensive modeling than using the two modeling techniques separately.

This document demonstrates a possibility for extension of the LYEE methodology by using the Enterprise Modelling approach. The Karlstad University unit undertook the work. The major contribution of this report from the practical point of view is to illustrate by various examples how enterprise modelling approach can contribute in the phase of system requirements engineering in the context of LYEE. The overall investigation is based on examples of a real case study in the area of e-commerce. Most software methodologies are heavily centred on system development issues at the implementation level. Thus, such methodologies are restrictive in a way that a supporting technical system specification can not be motivated or justified in the context of organisational process models. A blueprint of enterprise infrastructure provides a basis for the organisations information technology planning. It is sometimes referred as enterprise architecture. The major theoretical effort of this report is to demonstrate the Lyee software engineering methodology extensions by using the enterprise modelling approach. The main focus is on the issue of the pragmatic, semantic and logical software requirements integration by using the enterprise models.