The idea behind the Concept Presentation System (CPS), which is a service, is to build a facsimile / simulation of the solution that looks like a final solution while in fact it is a "shell".
The CPS is typically a month of programming that builds a "solution" that looks like the real thing. During this period the team focuses on the necessary items in order to create the "solution". It's more than a demo, but it's not a prototype, in fact its a combination of the two. The CPS gives you something to demo, but is not to be given to end users. This enables us to pact in a lot of features
As it's a fixed one month of programming the system is built for a small fixed cost. But it's not throw away code either, as it will be utilized in further development of your project. The other idea with the CPS is to create a "corner stone" from which to build the rest of the system.