We are planning a program of research and development aimed at integrated systems testing of critical components comprising the front end of the Project X linac at Fermilab. This program is being undertaken as a key component of the larger Project X R&D program. The successful completion of this program will validate the concept for the Project X front end, thereby minimizing the primary technical risk element within Project X. Successful systems testing will also demonstrate the viability of novel front end technologies that will find applications beyond Project X in the longer term. Integrated systems testing, known as the Project X Injector Experiment (PXIE), will be completed over the period FY12-16.