Irreversibile decisions, last responsible moment & Formula 1



Here I reflect about two concepts that Agile software development borrowed from Economics.



And how they relate to the pit-stop that brought Button to win the Australian GP, and how they relate to the Alonso decision to delay the exit on the track for the Q1 session of the Malaysian GP that brought Ferrari to the early elimination.




The concept of irreversibility was explained by Enrico Zaninotto italian professor in economics at the XP2000 conference: decisions the are irreversible, or to much expensive to revert,  are one of the prime drivers of complexity and all the XP practices strives to contain complexity by reducing irreversibility as opposed to tackling other complexity drivers.

XP practices have the potential to transform most of the technical decisions from irreversible to reversible, but not all.

The concept of the Last responsible moment, as defined by the Lean Construction Institute, come in help here: is the moment at which failing to make a decision eliminates an important alternative. When a decision is irreversible, it is fundamental to recognize it and to get to know what's the last responsible moment to make the decision. 




Let's go back to the decision made by Button to do the pit-stop at the lap 6 of the Australian GP.
Button made a reversible still risky decision in time, before the last responsible moment.  He went in pit from position 6 and 5 laps later reached position 2.

From the Race Lap Analysis document it is possible to calculate the cost to revert the decision to go in-pit and switch to the dry-tyres, that is about 22 seconds the time required to do another pit-stop: an high cost but still it's a reversible decision. The last responsible moment is before other opponent drivers switch to dry-tyres (otherwise there is no gain). The gain calculated from the Race Lap Analysis document  is about 11 seconds per lap, while most of the other drivers did the same at lap 8 and the direct opponents that where leading the race (Vettel and Webber) get in pit at lap 9 and 10 the total gain was from 22 to 44 seconds.


Let's look at the decision made by Alonso during the Q1 of the Malaysian GP.
Alonso made an irreversible decision after the last responsible moment when the rain on the track went from moderate to heavy. He and Massa were eliminated in Q1 and started the race from the bottom of the grid.

From the Q1 session lap times it is possible to estimate that the lap time increase because of the heavy rain was about +1sec.   Also from the lap times of the last tests sessions before the season began this relation between lap times and the heavy rain was well known. The decision to wait in the garage during Q1 with variable whether conditions is an irreversible decision. The last responsible moment is before the rain increase and this is unknown. A reversible decision would have been to go out on the track immediately and get in-pit to switch the tyres as soon as the whether condition get dry.




In my past experiences of software development I see a common mistake from the devs team to miss to recognize what are the irreversible technical decisions and to inform the stakeholder while I see a common mistake from the stakeholder to take actions only after the last responsible moment. This is how Agile sw development can sometime be confused as an excuse for improvisation and irresponsibility.


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Print | posted @ Saturday, April 10, 2010 6:37 PM

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