## 3 Results
### The Work as Done FRAM Model  
The [PERSON] video was then examined in detail and the actual timings for completing the various functions were obtained. These are given in Table 3.  
It is noticeable that in the video the overall time taken is less than predicted by our 'work as imagined' FRAM sequence of instantiations. So, the video was examined in more detail to try and establish how exactly the teams carried out their different functions. What adaptations were made to be able to complete the tasks more quickly?  
The first thing that becomes apparent when the videos [19] are examined closely is that although the officially timed start of the process is from when the car has stopped at its marks, the pit crews anticipate the stop, and the air guns are engaging, the wheel nuts and the jacks are moving into position before the car stops.  
This means that none of these functions are rate-determining in adding to the time but are effectively reducing the time by anticipating the start. In the WAD instantiation, below (Figure 7) we have thus added an additional function for the car to enter the box and be active before the \"official\" start time. Similarly, at the rear of the car, the jacks are removed as soon as the tyres are on and the release seems to happen simultaneously with the wheel-nut-tightening completion, another corner-cutting adaptation reflected in the changing the aspect links.  
There does not seem to be a noticeable delay in the release of the car, after the nut is tightened, which means again, that the release function is anticipating the clearance checks. Again, this has a significant effect in further reducing the overall time taken. In Table 4 below, the results of running the two FRAM models as imagined and as done, and rough timings taken from the Williams pit stop video are set out.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Assigned Function** & \begin{tabular}{c} **Time to React** \\ **Seconds** \\ \end{tabular} & \begin{tabular}{c} **Time to Complete** \\ **Seconds** \\ \end{tabular} & \
\begin{tabular}{c} **Time Taken** \\ **Seconds** \\ \end{tabular} &
\begin{tabular}{c} **Variability +/** \\ **Seconds** \\ \end{tabular} \\ \hline Stop car & 0 & 0 & 0 & 0 \\ Lift car & 0.15 & 0.2 & 0.35 & 0.2 \\ Stabilise car & 0.15 & 0.4 & 0.55 & 0.3 \\ Clean front wing & 0.15 & 0.5 & 0.65 & 0.5 \\ Clean rear spoiler & 0.15 & 0.5 & 0.65 & 0.5 \\ Remove wheel nut & 0.15 & 0.15 & 0.3 & 0.2 \\ Remove tyre & 0.15 & 0.35 & 0.5 & 0.2 \\ Replace tyre & 0.15 & 0.35 & 0.5 & 0.2 \\ Tighten nut & 0.15 & 0.15 & 0.3 & 0.2 \\ Lower car & 0.15 & 0.1 & 0.25 & 0.2 \\ Check complete & 0.15 & 0.15 & 0.3 & 0.2 \\ Spot gap & 0.15 & 0.15 & 0.3 & 0.2 \\ Release car & 0.15 & 0.05 & 0.2 & 0.2 \\ \hline \hline \end{tabular}  
* The FRAM can now be examined in more detail to probe where the system can be improved and made more reliable. Careful examination of other “record” pit stops reveals that modifications have certainly been made and the ‘work as done’ FRAM was put together to include these adaptations, as shown below.  
\end{table}
Table 3: F1 pit stop—Indicative timings of key functions needed.  
Figure 7: The ‘work as done’ FRAM model.  
When the Williams pit stop video is analysed more rigorously, we observe the third column timings. This is remarkably close to the WAD 231 timings, which further supports our interpretation of the actual work as done. As it is a very competitive environment and seconds saved in pit stops can mean gaining or losing advantage, there is continuing pressure to find ways of further reducing these times.  
One such initiative is rumoured to be the progressive automation of some of these critical functions like the release function, either for more speed, but more likely to be for more reliability/safety.