It is impossible to build a house without a carefully drawn design plan. If the building is a kennel, although the plan may not need to be so detailed, but still need some sketches, to be aware of.
Software development is completely different, and its "Design Plan" (planning) must be exhaustive and complete. For a long time, people don't have much structure in their development process, but those big projects can easily fail. Through continuous groping, people have mastered a large number of structures and detailed information. But their use is scary-it seems like you need to spend most of your time writing documents and not much time programming (often).
I hope it will provide a compromise for all that is told. You need to adopt a method that best suits your needs (and habits). No matter how small the plan is, there are some forms of planning that will greatly improve your project compared to the total lack of planning.
Keep in mind: According to the estimate, 50% or more projects without a plan will fail!