From the time Uchiyamada agreed to develop a hybrid concept vehicle in November 1994 until the deadline for the auto show in October 1995, there was less than a year to develop at least a workable hybrid engine and the vehicle itself. With extreme time pressure, the temptation would be to make a very fast decision on the hybrid technology and get to work on it immediately. Instead the team reexamined all its options with painstaking thoroughness (illustrating Principle 13). They used a “set-based” approach, considering 80 hybrid types and systematically eliminating engines that did not meet the requirement, narrowing it down to 10 types. The team carefully considered the merits of each of these and then selected the best four. Each of these four types was then evaluated carefully through computer simulation. Based on these results, they were confident enough to propose one alternative to the G21 team in May 1995, just six months later.
Up to this point, the focus was on concept development and research into alternative technologies. Now there was a clear direction for the program and technology to build the first mass-production hybrid vehicle. Toyota’s board could approve an actual budget, human resources, and a rough timeline. In June 1995, the Prius became an official development project. Since there was a great deal of new product technology as well as the task of developing a new manufacturing system, they developed a three-year plan. The first year would focus on developing a complete prototype. The second year would focus on working out the details through thorough research. The third year would focus on finalizing the production version and production preparation. Based on their best analysis, a stretch tar get of starting actual production the end of 1998 was forecast, with some cushion if needed to delay this until early 1999. They were very proud of their aggressive schedule.