Most Ministries of Health are highly regulated. Generally, large-scale projects, in order to be approved, require an authorizing environment, followed by preliminary legislative and regulatory approvals, the development of a financial model, and at least one other, final approval.
Obviously, the details of the approvals process can vary widely by government. But bureaucratic approval processes are a common feature of most Ministries of Health. Add in the regulations imposed by partner corporations, and the process of even getting a PPP off the ground appears significantly more daunting. For these reasons, PPP participants tend to choose pilot projects as a logical "first step." Some PPPs will even require multiple simultaneous pilot projects, as depicted in the SPV diagram in Chapter Two.
Pilot projects have a few key advantages. In most governments, they exist outside of the dense approval processes and regulations required of larger-scale projects. They are also quite a bit cheaper and can provide a proof-of-concept for a larger project down the road. Conversely, pilot projects face significant drawbacks. Their limited scope can reduce their effectiveness, so it can be difficult to approximate the effectiveness of a large-scale project using only a pilot as a model.