Question

1. Explain the differences between fixed and random factors in Design of Experiments (DoE).

2. Explain the three pillars of DoE.

3. What are the differences between replication and repetition?

4. In plastic injection molding, temperature, time in mold, and injection pressure each play an important role in determining the strength of the part. At MAR Inc., experimenters are studying the effects on part strength when the temperature is set at either 250o, 275o, or 300oF; the time in mold is either 5, 7, or 9 seconds; and the injection pressure is either 200, 250, or 300 psi. Create a table show the factors and their levels for this information.

5. For the information in problem 4, how many tests would be necessary to test every possible treatment (a full factorial experiment)?.

6. A team is currently working to redesign a compressor assembly cell. The team has several design changes that they want to test using design of experiments. They want to decrease the cell’s assembly and packing throughput time. Currently, it takes 45 minutes to assemble and pack a compressor. The team is considering three changes: Reduce current 36 inch conveyor width to either 18 inch or 24 inch; Install new parts presentation shelving, either flat surfaced or angled Line form: either straight or curved Implement the first four steps of the experiment design process in slide 15. Comment on how to interpret and verify the results

Answer 1

1.You can model a thing as random or fixed depending on our aim or the purpose of the model.The fixed effects r modelling the real thing in the world that we are trying to ,easure whereas random effects are just accounting fir variations due to our sampling.Simply speakin random effect model means we are studying the variability of a subset selected from a larger set and in fixed effect model,we are studying mean effect of factors.

2.Broadly there are 3 pillars of DOE...1.AESTHETICS

2.FUNCTIONALITY

3.USER EXPERIENCE

Aesthetics means how well the product is developed to enhance the use of application.It helps to understand the information in a easy way.Functionality means to fulfill the functions which was intended by the user.user experience means to make the product enjoyable to user,that needs human behaviour study before designing the product.The sociological and artistic ability of designer is used here.

3.Repetition means to study a process by measuring multiple sets of data,here available data is large and similar in nature.We keepon taking multiple samples from large data and measue it again and again.Replication means same experiment is repeated by another person,ie w=someone redo the entire same experiment.Here we use the same sample space,only the scientific investigator changes