  Quantum instruments represent the most general type of quantum measurement,
as they incorporate processes with both classical and quantum outputs. In many
scenarios, it may be desirable to have some "on-demand" device that is capable
of implementing one of many possible instruments whenever the experimenter
desires. We refer to such objects as programmable instrument devices (PIDs),
and this paper studies PIDs from a resource-theoretic perspective. A physically
important class of PIDs are those that do not require quantum memories to
implement, and these are naturally "free" in this resource theory.
Additionally, these free objects correspond precisely to the class of
unsteerable channel assemblages in the study of channel steering. The
traditional notion of measurement incompatibility emerges as a resource in this
theory since any PID controlling an incompatible family of instruments requires
a quantum memory to build. We identify an incompatibility preorder between PIDs
based on whether one can be transformed into another using processes that do
not require additional quantum memories. Necessary and sufficient conditions
are derived for when such transformations are possible based on how well
certain guessing games can be played using a given PID. Ultimately our results
provide an operational characterization of incompatibility, and they offer
semi-device-independent tests for incompatibility in the most general types of
quantum instruments.
