Abstract: A general purpose computer is programmed to provide graphic representations of the mechanical and electrical systems of an operating plant where all of the components are treated as "objects" and associated through a relational database with text files providing component specifications, product identifications, component operating status, and all directly interconnected components including data as to flow direction and relative position in the system. For maintenance and service each component is associated with existing and future specified work orders, service requirements including consideration of probable life expectancy and the like.