Method and apparatus for interfacing a manager and a plant

An interface between a manager and a plant;

• comprising
• a) means for the provision of a parent object representing child objects, each child object representing at least one resource of said plant;
• b) means for accepting a command from said manager indicating said parent object and an operation;
• c) means for attempting said operation in respect of resource represented by said child objects;
• d) means whereby each child object includes an indicator of the current state of a resource represented by said each child object;
• and
• e) means whereby said parent object includes an indicator of the current state of said parent object, said parent object state indicator based on said child object state indicators.

A computer readable medium storing computer executable instructions comprising:

• a) means for the provision of a parent object representing child objects, each child object representing at least one resource of said plant;
• b) means for accepting a command from said manager indicating said parent object and an operation;
• and
• c) means for attempting said operation in respect of resource represented by said child objects,
• wherein each child object includes an indicator of a current state of a resource represented by said each child object and wherein said parent object includes an indicator of a current state of said parent object, said parent object state indicator based on said child object state indicators.