When I started my career, I generally thought that projects proceeded like the first chart below, which plots entropy as a function of time. You start with a high number of unknowns at the proposal phase. There’s a lot of work in the PDR (Preliminary Design Review) phase to understand the problems and put together a feasible design. Then you refine it in the CDR (Critical Design Review) phase, build it, and you’re on your way to space.

However, I’ve found real life to be much more like this second plot. You start around the same area and convince yourself you have most of the problems solved by PDR. But their reality hits. You realize a bolt needs to be bigger but it won’t fit. You need a stiffer structure which breaks the mass budget. A key vendor pulls out. That special fastener you were going to use has a 37 week lead time. You scrape by CDR with only a couple dozen action items and then the real fun starts. You have some test failures and need to re-design. A part gets lost in shipping in receiving. The machine shop ruins an irreplaceable assembly. Somehow you get it all sorted out and delivered for flight, but not until the whole project is over budget and behind schedule.

I’ve come to fear the phrase “success oriented.” Projects regularly under-bid and over promise to get selected. The schedule looks good at first, but only if everything goes right. No one (including myself admittedly) seems to be able to plan for the inevitable issues and failures yet they always show up.