I like to only commit to a short elaboration, several weeks of documenting the state of the current project and coming up with a plan to get it on track. I then

I like to only commit to a short elaboration, several weeks of documenting the state of the current project and coming up with a plan to get it on track. I then offer the client the option of continuing, almost always at T&M at this point, or they can take my write up and shop it around. The plan generally starts with a "stop all new work and stabilize" phase; getting code metrics and an idea of technical debt; fixing processes, builds, making sure testing and QA is in place; and so on before any new work is done. Any client that isn't willing to pay for these things is just replacing one bad implementer with another.