Also, how is success vs failure defined? Whether you implemented what you intended to on time and on budget? That's a reasonable definition, but it doesn't cap

Also, how is success vs failure defined? Whether you implemented what you intended to on time and on budget? That's a reasonable definition, but it doesn't capture whether the project actually achieved the business goals it set out to achieve. For many projects, it's better to fail quickly than to succeed and then discover afterwards that it wasn't worth doing the project.