Tolerance Analysis OptQuest Solution

The goal of the following solution is to maximize quality while minimizing cost.

Note:

Except where indicated, this example uses the recommended Crystal Ball run preferences. See Setting Crystal Ball Run Preferences.

  To run the optimization:

  1. Be sure Tolerance Analysis.xls is open in Crystal Ball and the maximum trials and Latin Hypercube sample sizes have been set to 2000 as described previously.

  2. Start OptQuest.

  3. On the Objectives panel, set the objective to: Maximize the Zst total of Assembly gap.

  4. Set the following requirements:

    • The Minimum of Assembly gap must be greater than or equal to 0.0030 in inches

    • The Maximum of Assembly gap must be less than or equal to 0.0200 in inches.

    • The Final Value of Total assembly cost must be less than or equal to $60.00 dollars.

  5. Click Next to step through the problem and notice the following:

    • This problem has seven decision variables, one for the quality specification for each assembly component, with a continuous range between 1 and 5 sigmas.

    • The problem has no constraints.

  6. On the Options panel, click Advanced Options and select Automatically stop after 500 non-improving solutions.

  7. Run the optimization.

The cost and quality solution values appear in Figure 53, OptQuest solution for maximum quality with a cost requirement. The assembly gap Zst-total is 3.57 with a total assembly cost of $59.99. Decision variable values range from 3.5 to 3.9 sigmas.

Figure 53. OptQuest solution for maximum quality with a cost requirement

OptQuest solution for maximum quality with a cost requirement.