15. The method of claim 11 wherein the plurality of constraints include a structural constraint that imposes a restriction on how tasks are included within the instance template.
11. A method of flexible workflow management, comprising: storing a configurable task set in a storage medium, the configurable task set including a plurality of tasks and a plurality of constraints that define relationships between the plurality of tasks, each constraint of the plurality of constraints corresponding to a constraint type of a plurality of constraint types, wherein the plurality of constraint types includes at least one structural constraint type and at least one containment constraint type; creating a workflow process model using a process modeling tool, the process model including the configurable task set; simplifying a specification of the plurality of constraints for each constraint, using a constraints validation engine, by resolving intra-constraint conflicts for each said constraint type to provide a minimal specification for each said constraint of the constraint type, wherein for each said constraint type, said resolving is performed by (1) examining the plurality of constraints for transitivities and redundancies, (2) where possible, capturing any transitivities and removing any redundancies detected, and (3) employing a minimum cover algorithm when the constraint type is structural and a truth table algorithm when the constraint type is containment; resolving inter-constraint conflicts between each of the plurality of constraint types, taking into account any redundancies and/or transitivities detected between the plurality of constraint types; validating the plurality of tasks and the plurality of constraints such that each of the plurality of tasks are includable in at least one task subset without violating any of the constraints in each of the minimal specifications of the constraints; creating an open instance by copying the process model using a workflow engine; and activating the configurable task set during execution of the open instance to thereby compile and execute an instance template including a selected task subset of the plurality of tasks.