1. A real-time activity based accounting system including a computer usable medium having computer readable program 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, the plurality of sensors configured to detect a plurality of mutually distinct process variables of the manufacturing process; the plurality of sensors selected from the group consisting of flow meters, weight sensors, volume sensors, velocity sensors, pressure sensors, temperature sensors, analytical measurement devices, counters, voltage sensors, current sensors, meters, timers, valves, switches, data logging devices, and combinations thereof; said sub-plant accounting modules including a 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, and for generating journal entries for posting to an accounting module wherein appropriate accounts are debited and credited; 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, including the journal entries, 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 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 process historian, the translation module, the production model accounting database, and the accounting port, to the accounting module.