1. A computer-readable medium having computer-executable instructions for causing a computer to perform steps comprising: provide a declarative feature that is operable to allow a plurality of partially ordered steps in an extensible process spanning multiple application components to be defined in a declarative format, the declarative feature allowing at least some of the partially ordered steps to have an associated step action; and provide a sequencer that is operable to assemble the plurality of partially ordered steps together from the multiple application components into a computational sequence having a total ordering, and to execute the computational sequence in the total ordering upon receiving an execution request.