If there was an extended Goldratt universe, along the lines of the Marvel Cinematic Universe (“MCU“) then Rules of Flow has now added two new athletic activities – weight training in RoF 15 “Enough Weight, Enough Repetitions” and now a long day out cycling with Marc and his nephew Jack. Marc focuses on time as the constraint to their capacity to go riding, while his nephew gently reminds him that their power – a function of their training, nourishment, and energy – is also a constraint. They must meter their food and water, otherwise they won’t be able to complete the circuit they’ve chosen.
Best Writing, Quotes
“While Dave makes sure they have everything they need, Marc rides in circles in the driveway, getting used to the bike and reacquainting himself with using clip-in pedals.” Page 137, Dave has the full kit available for Marc, because his father, Jack, is a cyclist.
“You might want to pace yourself.” Dave says to Marc on Page 138.
“He needs to find a way to explain this to his uncle.” Page 138
- Dave gets his uncle to see his point by asking his uncle to explains something to him.
- This is very similar to the Socratic method used by Jonah in The Goal.
“In our case, we had six or seven hours of daylight, so I asked you to choose a route of four to five hours and left a couple of hours as a buffer.” Marc explains buffers to Dave on Page 139.
“If you run out of energy, you’re in trouble. So, in addition to time, there is something else that we need to watch today, and that’s our energy.” Dave explains to Marc that time is not the only constraint, Page 140.
“All the food we have for the ride is what’s in our pockets.” Dave explains to Marc, Page 140.
“We can’t afford to run out of power, but we don’t want to eat too much, either.” Dave to Marc, Page 141.
“When something important is at stake, you better have buffers.” Page 141.
“Once they started to implement the rules of flow, the work got tight; they let go of a lot of safety. But unexpected delays are bound to happen, and they have no buffers.” Marc recalls his concerns from the end of Chapter 22 now at the end of Chapter 23, Page 142
Fred Lybrand 
1. Rules of Flow now includes weight training and cycling as athletic activities.
2. Time and energy are both constraints that need to be managed during cycling.
3. Dave uses the Socratic method to explain the importance of energy management to Marc’s uncle.
4. Buffers are crucial when something important is at stake.
5. Unexpected delays are bound to happen and there should always be buffers.