GRIDSEARCH

GridSearch is the quickest way to find the sweet spots in your experiment.

GridSearch compares predictions from your data with your goals, and finds the points which meet all of your goals. These points are your sweet spots.

GridSearch is fast and easy to use. One STRATEGY(tm) user found the sweet spots in a four factor problem in 5 minutes. There were three responses, each fitted with a quadratic model.  Without GridSearch, 867 contour plots would have been needed to find this sweet spot. The details of this example are enclosed.

After GridSearch tells you where the sweet spots are, then use our 3-D Graphics in color to make contour plots showing the sweet spots.

Diagrams also available via fax

AN EXAMPLE OF GRIDSEARCH

In this product development example, there were four factors:

Temperature: 25 - 450 degrees F
Pressure: 20 - 60 psi 		Time: 1.0 - 5.5 hr.
Flow Rate: 6 - 70 cc/min

Three responses were of interest: Growth, Resistance, and Cost.

The Question to be addressed was:

"Is it possible to set temperature, time, pressure and flow rate so that the resulting growth is less than 500, the resistance is between 8 and 12, and the cost remains below $10?"

The budget was generous: a quadratic model was fitted by running a four factor interaction plus star design: 24 trials plus 5 replicates of the center point. An additional 15 check points were run.

Then b coefficients were computed by STRATEGY's regression analysis option. The model predictions agreed well with the check points.

GridSearch was used to locate the sweet spots.

GridSearch divided each factor's min-to-max interval into 16 parts and formed a grid that is 17x17x17x17. There were 24,905 of these grid points within the spherical region of interest.

GridSearch compared the model predictions at the grid points with the goals for each response and found:

52 points where Growth is <<500
3010 points where Resistance is between 8 and 12
17080 points where Cost is <<10

GridSearch found the sweet spots where all three goals were met: 

     X(1)    X(2)    X(3)    X(4)      Y(1)      Y(2)     Y(3)
     TEMP  PRESSURE  TIME    FLOW     GROWTH  RESISTANCE  COST
    131.25   40.0     5.2     46        494       9.6     8.3
    131.25   37.5     5.2     34        476      11.8     8.1
    131.25   37.5     5.2     38        462      11.3     8.2
    131.25   37.5     5.2     42        436      10.9     8.3
    131.25   37.5     5.2     46        397      10.4     8.3

GridSearch finds all the sweet spots! In this case all the sweet spots are adjacent; they form one sweet region. If you have more than one sweet region, GridSearch will find them all.

GridSearch found the five sweet spots in this example in less than 5 minutes. It would have taken 867 contour plots to find the sweet spots the old way. Here are the contour plots of the sweet spot to show the research team the shapes of the surfaces. In these plots time has been set at 5.2 and flow has been set at 46.

Goal: 8< Resistance <12

Diagrams also available by fax

 

Goal: Cost <10

Diagrams also available by fax

Goal: Growth <500

Diagrams also available by fax
Diagrams also available by fax
The Sweet Spot; where the  goals for all three responses are met.
Order STRATEGY today to speed up finding sweet spots in your projects.