The purpose of physics instruction is leading students to progress towards expertise in physics, to develop the ability to apply physics concepts to physical situations and reason with them, and to solve a wide range of problem types, including novel ones. Problem solving is central to physics instruction. Problem solving, however, as is traditionally used, is not as effective as it should be in achieving these goals and needs to be reconsidered. In this paper, according to results from physics education research, demonstrate that why traditional ways of using problem solving are ineffective for promoting true physics expertise and rethinking instruction and problem solving are explored. The purpose of physics instruction is leading students to progress towards expertise in physics, to develop the ability to apply physics concepts to physical situations and reason with them, and to solve a wide range of problem types, including novel ones. Problem solving is central to physics instruction. Problem solving, however, as is traditionally used, is not as effective as it should be in achieving these goals and needs to be reconsidered.