A new team, including myself, was brought in to take a second pass at the project. What we did was to 1) look at the data to make sure we had a valid data set, validated with the client 2) make sure we had standards to meet that were appropriate to the project and 3) started with a simple solution and then built more complex solutions. What approach 3) meant was that very quickly we had some solution in hand, and then we could proceed to imporve our solution through project iterations.
The project didn't work out in the end. The relationship with the client had been irrevocably poisoned by the previous failure.
But we were able to do the project the right way the second time.