You continue to interact with the simulation in the Prediction Profiler. I assume that you added the Response Limits column property to your response data column because you were able to maximize the desirability. Consider the variation of each factor. Is it fixed or variable run to run? How much does it vary, if it varies, and in what way (distribution)? What is the expected rate of failure? If it is very low, then you might be able to widen the distribution. If the failure rate is high, then you might tighten the distribution. You have to consider what controls the variation and the cost of control. JMP makes the simulation quick and easy, so you can iterate quickly over different factor settings and ranges to converge on an acceptable outcome.
I realize that this answer is somewhat vague. It highly depends on your situation.
A new tool is coming to the Prediction Profiler in the next version of JMP that was created specifically for this task.