The line graph compares the single fridge production duration for three manufacturers in years of 1990 and 2000.
Overall, the production time of a refrigerator in all three companies saw a decreasing trend generally from 1990 to 2000, whereas the duration changing for company B was relatively low within three companies.
In 1990, the company C spent the longest time to make a refrigerator, which was 35 hours. However, the company A and the company B spent much lower time to manufacture one refrigerator compared with the company A, within 30 hours and approximately 27 hours, respectively.
While the time turned to 2000, the manufacture time for one refrigerator in both the company A and the company C reduced dramaticlly. To be precise, the duration of manufacturing one fridge in the company A and the company C reduced by approximately 7 hours similarly, at around 23 hours in the company A and 28 hours in the company C. The inprovement of manufacturing time was relatively slight, with only about 2 hours time reduction in production process.
