I teach that you should seek to learn from competitors; obviously never copy another business's idea or what they are doing, but you can absolutely learn from their mistakes or see what they are doing and discover ways to improve it. All of that analysis belongs in your business plan: make sure you have your competitors under the microscope and make sure that is a solid chunk of your plan. That is some of the best research and information you will gather about what will make your business successful in future.
Look at the assumptions you baked into your original plan. Did the city follow through on opening that new park across from your location? Were insurance rates what you expected? How many hours of accounting or web design help did you really need? Are your online inquiries out_stripping your face_to_face sales? Or vice versa? Sometimes no matter how much you research, plan, or test, things don't go as expected in a business. This isn't necessarily a herald of failure or a sign that you're not cut out for entrepreneurship. Life and the marketplace are both unpredictable, and plans need to be fluid and responsive. The "One Pressing Issue Plan" is simply a reflection of a normal evaluation process.