What is the difference between curriculum development and curriculum planning?

Before you can develop something, you have to plan for it. For example, a school decides that their math program is NOT working. So they have a meeting to plan what to do. During planning, they evaluate what works and what doesn't'. Then, they make a development committee, and that group sits down with the information, and develops a curriculum, which includes scope, sequence, lessons, required equipment and materials, and time span, among other things. The plan has to come before the development, or they may end up with the same problems.