Methods, systems and computer program products for loading, storing and executing dynamically modifiable functional exercisers are provided. Aspects also include receiving a plurality of functional exercisers by a secondary reload memory disposed on a device-under-test. Aspects include loading at least a first functional exerciser from the secondary reload memory into a primary execution memory disposed on the device-under-test. Aspects include executing and modifying the first functional exerciser stored in the primary execution memory. Aspects further include, responsive to determining based on a test algorithm that one or more functional exercisers of the plurality have not been fully executed, loading a second functional exerciser from the secondary reload memory into the primary execution memory.