Improved tool and data selection in task management

Task management involves task creation and execution. These are facilitated using a task schema as exemplified in the Hercules Task Manager. Experience with Hercules has shown the task schema to be very useful for task creation, but less than ideal for task resolution, i.e., the selection of tool and data resources to be used in execution. Tool/data interactions often lead to resource selection constraints that cannot be captured using dependency relationships in the schema. We have addressed this by adding conditions to the task schema which use task-level meta-data to constrain resource selection. With examples we show that conditions are useful for handling a wide variety of real constraints.