It's the false mindset that believes the true value or benefits of a project or undertaking can only be realised upon its completion
Great callout here on the Arrival Fallacy, Ian.
It is so closely tied to the notion of “Big Bang,” lengthy “projects,” with massive up-front planning and risks given how little is known.
One helpful approach is the notion of “descaling the Vertical Slice,” just doing enough to learn, but doing it end-to-end.
For example, let’s say everything is riding on connecting 3 Legacy Enterprise systems to pass complicated data sets to an external vendor.
That could easily take many months and many millions of dollars.
But if we instead just pick one Legacy system, and make a “Hello World” call to the vendor system, that might only take days or weeks at a tiny fraction of the cost.
And think how much everyone will have learned in the process?
Then we add “just a little more....” etc.