Configuring the Multifunction Optimization System Tool (MOST) Technique

The Multifunction Optimization System Tool (MOST) technique attempts to solve the design problem as if it were a purely continuous problem.

See Also
Multifunction Optimization System Tool (MOST) Technique
Configuring the Technique and the Execution Options
  1. From the Flow section of the action bar, click Optimization and drop it on the process diagram.
  2. Double-click Optimization .
    The Optimization Editor appears.
  3. From the General tab's Optimization Technique list, select MOST.
  4. In the Optimization Technique Options area, enter the following:
    OptionDescription
    Maximum Iterations An iteration consists of two phases. In the first phase, a plausible search direction is computed from the gradient of the objective function and constraints at the current design point. In the second phase, new designs are evaluated along the selected direction (cost: one run per design) until no improvements are found or until a constraint is violated. The two phases are repeated until the specified convergence requirements are met. This option controls how many of these pairs of phases will take place. The value type is integer. The default value is 40.
    Convergence Tolerance The convergence criterion for MOST. If the necessary Kuhn-Tucker optimality conditions are satisfied to within Convergence Tolerance, optimization is terminated. The default value is 1⁢ × ⁢10−4.
    Relative Step Size The relative finite difference step size for the creation of the linear process. The value type is real. The default value is 1⁢ × ⁢10−4. Other possible values are > 0.0.
    Minimum Absolute Step Size The minimum absolute finite difference step for the creation of the linear process. The value type is real. The default value is 1⁢ × ⁢10−4. Other possible values are > 0.0.
    Maximum Confirmation Runs The number of iterations that must satisfy the objective convergence criterion before optimization terminates. The default is 5.
    Minimum Objective Change The minimum value for objective change for optimization termination. The default is 1⁢ × ⁢10−10.
    Constraint Tolerance The acceptable constraint violation for feasible designs. The default is 1⁢ × ⁢10−4. Other possible values are > 0.
    Maximum Failed Runs The maximum number of failed subflow evaluations that can be tolerated by the optimization technique. If the number of failed runs exceeds this value, the optimization adapter will terminate execution. To disable this feature, set this option to any negative value (for example, –1). When this option is set to a negative value, the optimization will continue execution despite any number of failed subflow runs.
    Failed Run Penalty Value The value of the Penalty parameter that is used for all failed subflow runs. The default value is 1⁢ × ⁢1030.
    Failed Run Objective Value The value of the Objective parameter that is used for all failed subflow runs. The default value is 1⁢ × ⁢1030.
  5. Click OK to save your changes and to close the Optimization Editor.