Edited sentence: An automotive part can take four years to develop; two years in the prototype stage and two years to reach production.However, computer flow analysis has helped reduce lead time and costs.Not all products take this long, for instance a two-way valve produced by Johnson Controls only took 18 months.The initial cost can be as much as $8 million USD to produce a four cylinder engine manifold.Two of the major disadvantages of this process are the high cost and long development time