Technically, whenever your medical practitioner recommends a birth intervention — like induction, or attempting to initiate active labor — he should also tell you the potential risks and benefits. In an ideal world, you'd also be given alternative options to consider.
For example, on the subject of induction, your doctor could explain the choices of giving you oxytocin (Pitocin) intravenously, trying something natural first, or taking a "wait and see" approach before augmenting labor. If he thoroughly explains all three options, you can give true informed consent, which means agreeing to a procedure only after understanding what's involved.In practice, informed consent for many procedures is covered extremely quickly, way too fast for you to process the information and make an informed decision. Frequently, procedures are not explained at all, especially if they're routine (which doesn't necessarily mean risk-free), or the procedure is presented as if you have no other options. Even if you have an amazing medical practitioner who really explains your risks and alternatives, you may have difficulty thinking through decisions when you're in the middle of labor.
Creating your birth plan allows you to research your options when you're feeling calm and collected. You still may have to make difficult decisions in the midst of labor — after all, birth isn't completely plan-friendly — but at least for straightforward issues, you'll be ready.