Have you ever had an unsuccessful project and what did you learn?

For now, I will say not really an unsuccessful project but more a mismanagement of a subject on my current project. Looking back on the consequences, I realised that it could have been avoided by better internal communication. Today, to avoid the same experience, I have created a checklist where we discuss about the different topics. The next step is to start once all the stakeholders required agrees on the different points and when all the actions are closed

During my 3 years of apprentice boilermaker, me and my mentor we were working on a aluminum project that was very sensitive in a way that we had like 0.5 tolerance to play with. We made a few mistakes to it because we thought we knew what we were doing. And the experience I gained through the project is that no matter how good you are at your job, don't take advantage of that because you end up not paying attention to small details. And most of the small details they tend to be the most important ones, so pay close attention to details.