In an ambitious hardware development project, it is very common to achieve a situation when the end of the road seems to be at reach: you went all the way through a challenging design phase, and you prototyped a few concepts that you iteratively improved until reaching a good confidence level that all initial requirement can be fulfilled. The project manager at this point has already filled the Gantt chart bar to a comfortable 90%, and already anticipate that tiny shot of dopamine that fires in his brain upon marking the task as “Done“. But here is where the wise engineer cools down the mounting enthusiasm:
“Yeah, we do see the end of the road…but perhaps there is a river in between”.
I heard that in a meeting today, and it struck me by lightning. For once, because I happen to be in that very situation!
It was July 2014, and I was on a off-road trip in Iceland with my father and my brother. We were driving a well equipped off-road vehicle, a Land Rover Defender with snorkel and oversized wheels: the kind of vehicle that you need to cross the mighty inlands.
Despite Iceland is quite famous for its off-road itineraries, there are plenty of paved roads, which for a Defender’s driver are evil, as gravel roads would be for a Ferrari. So we tried to take, whenever possible, detours that would bring on gravel and muddy stretch of roads, where we could enjoy the childish fun of driving full-speed through mud pools, and crossing small ponds and and creeks.
In one of these outings, we drove four hours on a challenging road among lava fields and the kind of rocks that do not make good friendship with your tires. The wether was chilly and the sky covered with gray cloud, from time to time dispatching a bit of their liquid load. According to the GPS, we were approaching the end of the road: a T-connection bringing us again on the main paved road and thus, in few minutes, to our next camping destination.
Doesn’t it sound a bit like when at the end of a long engineering study, after you went all the way through troubles and obstacles (and if you are a real engineer – like a real off-road driver – had a lot of fun doing it), a solution seems to be at reach? Well…
I tell you: there was indeed a river – just few hundred meters from the main road connection. And a big one! And there ain’t any bridges for God sake!
So what do you do? Go back all the way to the starting point?
What’s the analog of the river in the engineering world?
Suppose you had to prototype a certain electronics subsystem. You devised concepts and selected them after careful tradeoffs. You picked up couple promising ones, and made a design, schematics, and layouts. You ordered PCBs and expensive electronics components, and spent days populating prototypes, and testing and debugging them. On the way, you had to cross several creeks and mud pools: once you solved a problem here, you opened another there. That quick and dirty prototype, was definitely not quick, but you rather became very dirty along the way. Problems emerge wherever you would least expect them. Eventually, you end up with a 90% solution that fulfils all but one requirements. And there lies the manager’s bias: to consider that the end of the road is at reach.
When the engineer is asked by the project manager “what’s the progress”, he rightfully replies 90%. And he is right: he ended up in a local minimum of the whole solution space to the problem under investigation, which is 90% as deep as the global one. The problem is that the global minimum can be just slightly off the current spot, or miles away (like it can happen in chemistry in the optimization of complex molecular structures).
Never forget that a river may be hiding just behind the last turn and you will avoid one of the most common project manager’s pitfalls .
That is my lesson learned for today. And if you are curious to know how it ended up with my small off-road adventure: eventually, we sent my younger brother on ahead in the freezing water of the mighty river to check the depth and the stability of the bottom. That’s what they write on the off-road driving best practices after all. There was some pretty big rock along the way. A bit of a bumpy drive, but we made it in the end. And it was definitely a lot of fun!