The provided line graph illustrates the required time for the manufacture of a vehicle by Nissan, DC, GM, and Ford in 4-year period, commencing from 1988.
Overall, except for Ford, the production time of Nissan, Daimler Chrysler and General Motors showed a downward trend. Additionally, although Nissan spent the highest amount of time per vehicle in 1988, its manufacturing time in 2002 was fastest.
In terms of US car producers which reported constant decrease, in 1988, it took 37 hours for Nissan to finish one vehicle, 5 hours more than that for GM. An identical figure was seen in 1999, with both manufacturers allocating approximately 30 hours to each vehicle. After that point, GM spent roughly 2 hours less yearly, while the data for Nissan plummeted to 24 hours in 2000 before gradually dipping to just 21 hours in 2002.
As for the remaining producers, DC allocated 34 hours for each car in 1988, far exceeding that spent by Ford (25 hours). After a diminishing pattern to nearly 32 hours in 1999, the amount of time for each DC’s car levelled out for the next 2 years. In contrast, Ford spent more and more time producing vehicles over the next 3 years, bridging the gap between its and DC’s time. In 2002, the former needed 26 hours and the latter spent 28 hours manufacturing every vehicle.