1. A method of automatically scheduling maintenance orders within a process plant comprising a plurality of assets, the method comprising:generating, in a maintenance planning computer, a maintenance order in response to a maintenance alert for one of the plurality of assets;
generating, in the maintenance planning computer, estimated maintenance information for the maintenance order, the estimated maintenance information indicating an estimated time or an estimated cost associated with the maintenance order, where the estimated time or the estimated cost varies depending upon maintenance information for at least one other maintenance order corresponding to a different asset, the estimated maintenance information being stored as a data table accessible by the maintenance planning computer, the data table including a field for cross-referenced maintenance orders;
receiving data from at least one asset, executing models from among a plurality of computer-implementable models stored at the maintenance planning computer, and generating for the at least one asset, a health index, a performance index, a usability index, or a variability index, from the received data and based on one or more of the plurality of computer-implementable models;
scheduling, in the maintenance planning computer, the maintenance order using a multi-variable model from among the executed models, the multi-variable model being based on the generated health index, performance index, usability index, or variability index, where the maintenance order is scheduled among one or more other maintenance orders, the scheduling resulting in a maintenance schedule that includes the maintenance order; and
in response to detection of a delay in an active maintenance order, determining if that delay affects the scheduling of the maintenance order of any of the one or more other maintenance orders, and, if so, re-scheduling the affected maintenance order and any of the affected one or more other maintenance orders, wherein determining if that delays affects the scheduling includes determining if there are any cross-referenced maintenance orders stored in the data table, and wherein re-schedule includes determining whether to re-order the affected maintenance order and determining whether to instead delay the affected maintenance order and the cross-referenced maintenance orders,
wherein generating the maintenance order in response to the alert further comprises (i) collecting historical data of at least one previous maintenance order corresponding to the maintenance alert; (ii) determining the estimated maintenance information based, in part, on the historical data compiled from past maintenance orders; and (iii) if no historical data is available then obtaining other historical data compiled from past maintenance orders on a comparable asset via a remote monitoring facility and through a communication network,
wherein the maintenance planning computer is configured to receive the data in response to the executed models and wherein at least some of the received data is formatted in a descriptive language, the method further comprising the maintenance planning computer mapping the received data in the descriptive language from one schema to another schema in accordance with the executed models.