Sundown of the twentieth century saw the emergence of the World Wide Web. A decade later, semantic web (SW) envisioned enriching of web-accessible information and services with machine-processable semantics to solve the problems of information management and sharing which are aroused by the success of the web. However, success of the SW largely depends on the availability of formal ontologies for representing and structuring information in different domains. To facilitate web ontology engineering (OE), methodologies are proposed by the researchers since years. However, OE particularly web OE is still immature and none of the methodologies is standardized for web OE projects as yet. This paper presents an evolutionary SW ontology engineering methodology called POEM. POEM presents a complete methodology comprising of various phases for performing conceptualization, designing, implementation, evaluation, and project management tasks. POEM exploits and incorporates the large experiences from the widely used software engineering standards to make the methodology more realistic and provide greater functionality. Due to its broad nature, POEM has the potential applicability in a wider range of OE projects. Comparison of POEM with other OE methodologies has ascertained POEM as more advantageous and easy methodology for SW ontology engineering.Most of the development projects fail due to lack of proper methodologies and management. Semantic web (SW) turns the web of information into web of knowledge and enables people and computers to work in cooperation by giving well-defined meanings to web resources. However, success of the SW depends largely on the availability of web ontologies. Building SW ontology is a complex task and requires careful understanding, planning, and management like software development projects. Clearly, a comprehensive methodology is essential for handling the technicalities involved in an SW ontology engineering project. This paper presents a comprehensive methodology called POEM which consists of detailed steps from inception to implementation of SW ontology. POEM leverages valuable concepts and experiences from software engineering to provide an easy and practical approach. POEM outperforms the available methodologies by vibrantly supporting the ontology project management activities equally to the core ontology development activities.