Parameters are constraints that have variable names. They can have either numerical values or values based on the result of mathematical expressions involving other parameters—parametric equations. Parameters can be associated with dimensions in the current sketch, or they can be numerical constants and expressions independent of the sketch. The value of parameters associated with dimensions directly affect the sketch, whereas independent parameters affect the sketch only if you use them to create expressions for parameters that are in the sketch.
You add and edit parameters using the Parameter Manager. You can use the Dimension button to create new parameters by selecting dimensions, or you can add independent parameters by typing them in blank lines in the manager.
To add or edit a parameter:
From the tools in the Sketcher toolbox, select the Parameter Manager tool 
. For a diagram of the tools in the Sketcher toolbox, see “The Sketcher tools,” Section 20.4.1.
The Parameter Manager appears.
Tip:
You can also open the Parameter Manager by selecting Edit
Parameter Manager from the main menu bar or by using the f(x) button in the Edit Dimension dialog box.
Click Dimension, and select dimensions from the sketch to associate them with new parameters.
Abaqus/CAE adds the new parameters to the Parameter Manager using default names of the form dimension_x.
Click on a cell in the Name column to edit an existing name, or add a new parameter name by editing a blank cell.
If the selected parameter is associated with a dimension, Abaqus/CAE highlights the parameter in the sketch.
Click on a cell in the Expression column to edit it directly in the cell or to select it for editing with the Expression Builder.
You must define all the parameters that you want to use in an expression prior to defining the expression.
Tip: Use the buttons on the right side of the manager to insert, rearrange, or delete rows.
If desired, use the Expression Builder to edit the expression. For detailed instructions, see “Creating parametric equations,” Section 20.12.6.
Click Apply in the Parameter Manager to implement your changes in the sketch.
Abaqus/CAE updates the sketch with any new expression values and, if Show parameter names is toggled on in the Sketcher Options, displays the revised parameter names.
