Journal 13: The topic of my reseach paper

I have a course called "introduction of optimal design" in this semester, and I"m considering why the optimum design is so important and neccessary in engineering technology.  Therefore, I searched information about " optimal design" on wikipedia, and I found optimal design is a class of experimental design, and the design of experiments is very important and neccessary in engineering technology. Finally, I made a decision on my research question- Why is the design of experiments important in engineering technology?