Large business enterprises rely heavily on their human capital. The human capital consists of domain knowledge, experience, analytical and creativity levels. It is recognized that, creativity levels and analytical skills are traits of individuals. All these need to be captured by the use of suitable knowledge capturing techniques, particularly due to exponential knowledge growth in all domains of technology. Ontological modeling has the potential to capture such knowledge, and organize it in a structured format based on the concepts and their mutual relations. It can capture the analytical and creative rationale of design and troubleshooting, besides incorporating specific design sub-routines for tasks. This paper discusses an ontology based model, which stores knowledge for the positioning-system of steam turbine rotor. The efficacy of the model has been demonstrated in capturing this domain knowledge, which can be used by the design and the maintenance personnel and thereby, increase their efficiency.