Manufacturing equipment, such as numerical controlled machines and assembly cranes, requires constant maintenance and service in their operating lifecycle. Equipment maintenance plays an important role in avoiding unexpected failures and ensuring production efficiency. During maintenance operations, much data is generated and stored in databases. It is essential for manufacturing companies to develop a system to integrate equipment condition monitoring, fault prediction and knowledge base to support maintenance decisions. A case study, carried out within a power generator manufacturing organisation, was conducted to understand what the maintenance process is and how maintenance knowledge is currently managed. It was concluded that maintenance process is less efficient, and maintenance records, stored within internal databases, are not consistent, which makes knowledge hard to share, learn from and reuse. This paper proposes a Knowledge Management System for Maintenance, Repair and Service in Manufacturing Systems to support better maintenance decision and improve maintenance efficiency.