WES uses a pre-commercial procurement model to drive innovation. This is effectively a technology competition, where a number of potential suppliers enter the programme through an open tender and then carry out a phase of development. At the end of the phase, the concepts are tested, and the best technology is taken through to the next stage for further development. This continues for 3 phases of development, until mature technology can be achieved.

The advantage of this approach to the suppliers is that they can receive up to 100% funding to develop their technology, and the public procurer can quickly identify the best technology through this competitive approach.