Some people give up too easily. They hit even a small road bump, and they just don’t go on. Yet others keep trying too hard and too long, way beyond the time when quitting makes more sense. When it comes to being a successful entrepreneur or small business owner, the trick is to know your sweet spot, the place when it makes the most sense to quit or when to keep on plugging away.

It would be great if there was an app to tell when to keep working on something and when to simply accept that you failed and let go. No such luck (but it’s a good bet that someone is working on one).

Every experience is different and each situation is unique. There’s no measurement device for persistence or clear-cut guidelines to let you know when to give up or push through. You must know your own “Rubicon,” defined as the point when “to take a decisive, irrevocable step.” You have to find your own point of “no return.”

Don’t give up (well, most of the time).

Sometimes it’s a good idea to stop. Sometimes not. The choice is up to you. But, here are a few questions I ask myself when I am making the decision to go on or not:

• Is my heart still in it?
• Can I achieve greater results by simply moving on to something else?
• Knowing what I know now, would I start this task today?

A friend told me about the physical therapy sessions she had a while ago, after she was recovering from a broken leg. The therapy often made her ache. But she kept on going, because she wanted to get back to her normal routine. The advice that the therapist told her stuck with me, “If it’s just uncomfortable, it’s a good idea to keep going. But if it’s painful, you should stop.”

The decision to continue in any business situation is much the same. If you’re going hard and too fast, it may cause temporary discomfort or even a minor setback. But, if you’re doing something wrong or injurious to you or your business, it’s time to stop. It all comes down to risk versus reward.