1. A system for allowing consistent execution of a workflow process in a computer-enabled workflow management system, comprising (A) a workflow process database accessible by the workflow process, wherein the workflow process includes at least one sequence of workflow actions, having at least one set of parallel workflow actions and being configured as a plurality of nodes interconnected by arcs, each node defining at least one of the workflow actions and reading and writing data items when executing the workflow actions; (B) a module that maintains execution consistency among the workflow actions when the nodes access the workflow process database to read and write the data items in carrying out the workflow actions while maintaining execution concurrency among the workflow actions, wherein the module further comprises (I) a first sub-module that locks a data item in the database when the data item is to be read or updated by one of the nodes and is not locked by other nodes before the read or update operation is commenced, wherein the first sub-module causes the node to update the workflow process database with the data item if the data item was not previously updated by another node executing another action which has accessed the same action database of the workflow management system with a greater serialization order; (II) a second sub-module that releases the lock after the node has performed the read or update operation.