Advantages and disadvantages of OFAAT and DOE

Per the textbook, trying to understand factors that impact the outcomes of business process is an important aspect of improving business operations. Conventional wisdom plans experiment one-factor-at-a-time (OFAAT). 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.

Design of Experiment is the best way to go when you want to make effective changes in a program or if you want to create a program.  Detailing each item step by step reveals the plans of the product in a more inviting and intriguing manner. While the One-factor-at-a-time does just what it says, one at a time.  When using the Design of Experiment, you have so many ideas to choose from that will display in full what each entity stands for and how together it will become a beautiful project that will add depth and creativity to an office or business.  A business could very well be based off of a Design of Experiment.  With every detail laid out a company can flourish if the steps are followed consistently.  Ex. Our company schedules a yearly staff retreat for the entire company for two days.  The staff choose which of the days they would like to attend.  Once the numbers are calculated, then the busiest part of the plan can begin.  There is so much to be done such as the snacks, games, plans for the future, more games, skill-building, Team-building, lunch for the entire crowd for 2 days along with breakfast and more snacks, etc.  there is so much that goes into this retreat that we don’t see and it takes several teams to come together to get this project done. If they were using the One-factor-at-a-time design, it would take them forever.

Answer 2

One-factor-at-a-time (OFAAT) consist of trial and error, intuition and guesswork and experience. Such experiment changes one factor at a time while the other elements remain fixed. The OFAAT also requires fewer resources compare to DOE. The disadvantage of OFAAT is interaction between causes is not  measurable due to no information which can mislead the optimal circumstances of the process. Also, it takes longer to examine all the factor’s when testing one at a time. Next, performance is low in the presence of interacting process variables. Last, each trial run by comparing the detected outcome with prior results make the estimation of the factor effects less precise.

Design of experiment (DOE) is a powerful tool used to determine the factors that cause adjustments in the answer and foresee them in a coherent mathematical system.  DOE is beneficial where traditional engineering analysis, verification, and simulations are challenging to obtain. A major point of this process is that it changes several variables at once. The more variables investigated then new combinations are required. On the other hand, the disadvantage of DOE is a failure to control individual variables, as well as it relies strongly on statistics. It is hard to recognize optimum settings due to a lack of importance in variables.

To obtain an efficient business process, the approach I would use is the DOE. Such measure recognizes the interaction between factors considered for the experiment which is not a part of changing one element at a time.

Answer 3

The one-factor-at-a-time (OFAAT) is the traditional approach to planned experimentation and in this approach each process variable (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 interacting process variables, the variation associated with the response (y) is small, thereby significantly reducing the effectiveness of the approach, and it takes a long time to test all the variables when testing them one at a time.

Whereas, by using statistical design of experiments (DOE) increases the ability to find the vital few key drivers of a process, understand the process, and build useful process models. This model is developed by quantitatively measuring the relationship between one or more process variables (x’s) and the process responses (y’s) simultaneously and still evaluate the effects independently, have control of the nuisance variables, it’s more effective than testing one factor at a time and regression analysis can be used to analyze the results of the experiments. Also, the experiment can be completed in a faster time than it would take for OFAAT and it produces better results overall. There are disadvantages of using multiple experiments, such as blocking, randomization, and center points.

Example: If my supervisor handed me a large about of data and told me that my assisted was needed to help improve our business process I would not experiment with OFAAT because it would take me too long to test each factor or change one factor and measure it again and again. I would use the DOE method because it gives me the ability to test multiple things simultaneously and still evaluate the effects independently. The independent evaluation gives me the ability to get root cause, the cause and effect relationships. If I can find the root causes of problems the decision making and financial aspect will be enhanced.