1. A real-time activity based accounting system including a computer usable medium having computer readable code therein, for a manufacturing plant having at least one manufacturing process, said accounting system comprising: a plurality of sub-plant accounting modules configurable to receive process data from a plurality of sensors associated with the manufacturing process; said sub-plant accounting modules including computer usable medium having computer readable program code therein for calculating a plurality of sub-plant accounting measures using the process data of the plurality of mutually distinct process variables, for posting to an accounting module; a process historian coupled to said sub-plant accounting modules; a translation module coupled to said process historian; the translation module configured to receive and aggregate the plurality of sub-plant accounting measures; a production model accounting database having a plurality of sections configured for modeling the manufacturing process in the manufacturing plant; the production model accounting database configured to receive and selectively place the aggregated accounting measures from said translation module into said plurality of sections substantially in real-time; and an accounting port operatively associated with said production model accounting database, said accounting port being couplable with the accounting module, wherein the accounting system is configured to supply substantially real-time, aggregated data from the production model accounting database to the accounting module; wherein the accounting system is configured to move data along a hierarchically upward data path from the sensors, to the sub-plant accounting modules, to the production model accounting database, the accounting port, and to the accounting module.