Service-Oriented Software Engineering (SOSE) is a software engineering approach, which utilizes the service constructs conforming to the Service Orientation (SO) and Service-Oriented Architecture (SOA) principles for identifying, designing, constructing, and deploying reusable services. These services are composed into Service-Based Applications (SBAS). The aim of this work is to propose a method that is based on best practices of the existing SOSE methods with an outcome of services that: (i) conform to SO and SOA principles, and (ii) is geared towards SBA development aspect of SOSE. In this thesis, a new SOSE method is proposed. It is based on a developed comparison framework, best practices of existing approaches, as well as extending and adapting certain aspects that are important for organizations that wish to adopt SOA. The method has mainly four phases: • Planning phase: collect requirements and informative entities of existing systems Identification phase; analyze requirements and existing systems to identify services • Design phase: describe service contract (interface), and protocol of services • Construction phase; deploy services with a modernization strategy To achieve the aim of this thesis, the following objectives were pursued: 1. A literature review of exiting SOSE approaches was conducted. 2. A comparison framework was designed, with criteria to identify how these methods differ. 3. Existing web services technologies are studied thoroughly and utilized to apply the proposed method to a case study based on a real-life scenario. The contribution of this thesis can be described as follows. Firstly, several authors stated that a comprehensive method for Service Engineering (SE) is missing, thus this thesis aims at filling this research gap. Secondly, this method provides organizations with a systematic approach to identify its computational capabilities from a service-perspective, thus SBAs that can be developed by composing these capabilities whenever requirements change.