Knowledge is the fundamental resource that allows us to function intelligently. Similarly, organisations (i.e., enterprises) typically use different types of knowledge to enhance their performance. Task ontology modelling is the key to corporate knowledge management via modelling shareable and reusable knowledge bases. The mapping between the domain specific task ontology, and the domain independent task ontology, is crucial for realising shareable and reusable knowledge bases. This paper suggests an approach to achieving this objective, by proposing a three phase knowledge engineering approach. Task ontology is modelled using MODEL-ECS (i.e., graphically based executable conceptual modelling language). Conceptualisation of the organisation and its knowledge base is crucial to formalising the mapping functions necessary to realise corporate memory modelling. This paper describes one such approach.