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 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 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.