Some Agile and/or ALM adoption efforts are canceled midstream because of lack of understanding of the basics of finding a suitable candidate development project. I have seen in more than a single situation that the chosen project is cutting edge in all three aspects of technology, process and people:
But the biggest mistake with Pilot efforts is to to use a strategic, high profile brand new project as the proofing ground for all these aspects, all at the same time. This is more common than expected. It starts as something like this:
To add insult to injury, sometimes on top of all this no proof-of-concept is ever tried with the new technology and processes (Proof-of-concept differs from pilot in that it is done in a lab environment, with no impact on business). Pilot projects do have business justification, but usually one chooses a minor project instead of betting the "jewels of the crown" on risk upon risk.
The mistake on all these lies usually in the governance management tier(PMO, office of the CIO, etc). It is usually associated with just enforcing the status quo, and it takes some brand new business need to act as a catalyst to challenge it. This governance tier should be the one to understand how to evolve their environment through carefully taken steps, and to know how to spread the risk underlying the business need into preparatory small projects (using proof of concepts and pilots) that will pave the ground for more ambitious ones.
If a governance tier is not active in doing this, the new project decays into a rogue that just reinforces the "didn't tell you so" attitude of those who see governance only as keeping IT madness in straightjackets.
Allowing this to happen is like building on moving sand: the construction might be impeccable but will collapse upon itself if it doesn't have firm ground to support the pressure of adding new layers.
The best practices for selection of a Pilot project are widely known, and for quite a long time. Here is an excerpt from a Microsoft Official Curriculum course from 1993. It is part of Course 124 - Managing the Migration to Client-Server Architectures. I modified the text to fit ALM adoption (the text in brackets [] replaces "client-server" and updates the context of other points):
"Start small - with a Pilot Project
We suggest you start your exploration of [new ALM processes and tools] with a pilot project.
Selection Criteria of Pilot Projects
As you can see, those best practices are nothing more than codified common sense, and I highly recommend you have those in mind when scoping your next ALM project.