Question

Compare and contrast the main advantages and disadvantages of OFAAT and DOE and select the approach (e.g., OFAAT or DOE) that you would use in order to obtain effective business process. Provide a rationale for your response. ​

Answer 1

The OFAAT is the traditional approach to planned experimentation and in this approach each process variable or factor is studied individually by varying the variable X and measuring the response Y while holding all other variables constant. There's only one peak and one valley and performs poorly in the presence of interecting process variables,the variation associated with the response variable Y is small thereby significantly reducing the effectiveness of this approach and it takes long time to test all the variables when testing them one at a time.

Whereas, by statistical design of experiments DOE increases the ability to find the vital few key drivers of a process,understand the process and build a useful process models.This model is developed by quantitatively measuring the relationship between one or more process variables X's and process response Y's simultaneously and still evaluate the effects independently,have control of the nuisance variables,its more effective then testing one factor at a time and regression analysis can be used to analyse the results of the experiments.The experiments can be completed in faster time as compared to the OFAAT and it produces better results overall.There are disadvanteges of using multiple experiments such as blocking ,randomixation and center points.

Lets say we have a large amount of data and we are to improve our business process then I would not experiment with OFAAT because it would take too long to test each factor or change one factor and measure it again ad again.I would use DOE method because it gives me the ability to test multiple things simultaneously and still evaluate effects independently.The independent evaluation gives me the ability to get the root cause, the cause and effects relationships.