notice the emphasis on "elapsed time". The use of elapsed time is probably very different from the guidance you have previously been given. Most other methodologies ask you to measure only the actual amount of time spent actively working on a given item (if they ask you to measure time at all). I happen to think this guidance is wrong. I have a couple of reasons why. First, and most importantly, your customers probably think about the world in terms of elapsed time. For example, let's say that on March 1, you communicate to your customers that something will be done in 30 days. My guess would be that your customer's expectation would be that they would get their item on or before March 31. However, if you meant 30 "business days" then your expectation is the customer would get something sometime around the middle of April. I am sure you can see where that difference in expectations might be a problem. Second, if you only measure active time, you are ignoring a large part of your predictability problem. It is the time that an item spends waiting or delayed (i.e., not actively being worked) that is usually where most of your unpredictability lies. It is precisely that area that we are going to look at for most substantial predictability improvements.