The next day, Alex receives a call from Bill, who is furious that Alex walked out on the meeting. This conversation distracts Alex from thinking about Jonah and the goal. That night, Alex wants to call Jonah, but realizes he does not have his number. He thinks the number might be in an address book in his childhood home, and so goes there to find it. He calls Julie to tell her he will not be home for dinner. She isn’t pleased. At his mother’s house, Alex finds the address book, and after calling several former classmates, manages to get a hold of Jonah. He proudly tells Jonah he has identified the goal, and asks how he can make his plant more productive. Jonah advises him that “‘there is more than one way to express the goal’” (59) and that he has developed a system of measurements that should help. The first measurement is throughput—“the rate at which the system generates money” (60). The second is inventory, the money invested in purchasing materials. The third is operational expense, which is all the money spent in order to turn inventory into throughput. Jonah has to end the call there, and Alex sleeps at his mother’s house.