When I was at NSF, we had a big problem child of a project, NEON, the National Ecological Observatory Network. Comprised of cyber-infrastructure, robotic sensors, human field sampling and airborne platforms extending from the Arctic Ocean to Puerto Rico, the nearly half-billion dollar project had chronic issues with costs and schedules. To fix those problems, the NSF brought in USAF Lt. General James Abrahamson because he had been the fixer-in-chief on projects as diverse as the F-16 and the Space Shuttle.
One of the things that the General taught us to do, as far as fixing NEON, was to use spiral development: build a little, test a little, build a little more, test a little more. We learned that one of the root problems with the NEON design was that it had been “frozen in place” back in the first years of the new century and hence was technologically obsoleted before we finished construction. Spiral development was one of the key approaches we used to fix NEON.
Here’s a new article in Space News on how that approach is being currently deployed in the USAF. It strikes me that this approach should be used in many science R&D areas where the time-line is lengthy and the consequences for failure are large.