A system may receive an input specification, compose a workflow by connecting an output port of a first one of a plurality of work units to an input port of a second one of the work units, receive a work order associated with the workflow, decompose the workflow into constituent work units upon receipt of the work order, instantiate tasks that correspond to the work units, generate a bill of materials that lists input and output files associated with the tasks based on the tasks and the input specification, and update fields of the bill of materials, the fields indicating states of the input and output files.