Do you need to plan if you have a course book?

Do you need to plan if you have a course book?
Most schools provide their teachers with a syllabus and materials for teaching that syllabus. This is often in the form of a
course book. Course books provide a variety of material in a structured way and can be a great benefit for the teacher and
the student. However, having a course book does not reduce the need for planning.
Here are some advantages and disadvantages of using a course book:
Course books are, without doubt, a very useful aid for teachers. However it is often more productive to try and adapt and
supplement the material in the book to suit your particular class. If you do use a course book, try not to follow the same
routine each lesson – vary the order of the activities and remember that it isn’t always necessary to do every exercise to
achieve your aim.
A course book can certainly help you to plan, but it cannot replace your own ideas for what you want to achieve with your
class.