To be able to base your plan on facts, the first thing is to collect facts. This is the reason why this topic is brought up as late as in the last chapter. If you followed the schedule in this book you should by now have metrics from 2 weeks of work, where you know how many items you can handle during two weeks, the average time to market, and the average time spent on an item. This is important information when trying to predict the future.

When looking at the facts you have you will see variation in both size of work and in how much time was spent working on your items during a day. Some days are focused with little interruptions while other days are spent in meetings and on unpredicted things.

To reduce the variation you need to take control over the amount of work and make sure you get your workdays more leveled out.