To reformulate is to rework or improve an original plan. If your bottle rocket goes off course, crashing into your kitchen window, you will want to reformulate the flight plans before you launch it again.
Fortunately for English speakers, there are a lot of linguistic opportunities for second chances! Reformulate is one of those words that give you a chance to improve upon a first try. Words in this “do-over” family include revise, rework, and redevelop; notice the re in all of these words, from the Latin “again” or “back.” Reformulate is usually used for a formula, theory, or plan.