There are two reasons a Reading Schedule is needed.
The first reason is that the Word Way program does not read straight through the Bible but moves back and forth between the Old Testament and New Testament. A schedule is necessary for the reader to know what the assigned reading is for each day. See Why does the Reading Schedule move back and forth between the Old Testament and the New Testament each week?
Secondly, the program is based on reading one chapter a day from the Bible. By reading only one chapter a day, it will take 170 weeks, or 3 ¼ years, to read through the Bible. Realistically, there will be situations where a person will not be able to read the assigned chapter for that day. For the times when a reader falls behind in reading, a schedule can help to track your reading progress and allow you to know what chapters need to be read.