Question

A quality analyst at Paintfast Manufacturing Co. wants to determine if a new paint formulation, used to paint parts for a customer’s assembly oper- ation will dry fast enough to meet the customer’s needs. The customer would prefer to obtain a high level of “dryability” at low temperatures, even if it requires a higher level of drying agent. He hypothesizes that a high level of drying agent will result in high dryability, high temperature— alone—will result in a moderately high level of dryability, and low temperature or a low level of drying agent will result in a low level of dryability. He hopes that the main and interaction effects with the temperature, which is expensive (because an oven would need to be used), will be minimal. The data found in the worksheet Prob. 6-24 in the Excel workbook C06Data were gathered in testing all combinations. What recommendation would you make?

Problem 6-24
Paintfast Manufacturing Co.
Description	Name	Low level	High level
Factor 1	Drying agent	10 mg.	20 mg.
Factor 2	Temperature	80 degrees	100 degrees
Treatment	Factor 1	Factor 2	Response=Dryability
A	Low	Low	78
B	High	Low	91
C	Low	High	85
D	High	High	87

Answer 1

The responses (dryability) at low Factor 1 are 78 and 85, while at high level of Factor 1, the responses are 91 and 87. Clearly level of Factor 1 has a linear effect on dryability. Thus higher level of drying agent is recommended.

Now looking at the effect of temperature. From the table it is observed that when Factor 1 is set low, the change in response between low temperature (78) and high temperature (85) is by 7 . Similarly when Factor 1 is set at high level, the change in dryablity between low temperature(91) and high temperature(87) is by -4.

Thus at low drying agent levels, an increase in temperature improved the dryability and at high drying agent levels ,temperature rise deteriorated the dryability.

If we look at the table from view point of Factor 2, the responses at low temperature are 78 and 91 and at high temperature they are 85 and 87. Thus an increase in temperate doesn't have linear effect on the response.

It can also be observed that at low temperature level, there is a large increase in the response (13) from low level of Factor 1 (78) and high level of factor 1 (91). Whereas at high temperature the change in response is very small (2).

Thus High level of drying agent and low temperature are recommended for the operation , which is also the preference of the customer.