Case Study Parameters and Results

Refer to Case Study Overview for a description of Case Study and the meanings of terms used.

Usage

Use this window to specify the changes you want to make to your input Parameters and to define the Results you want to examine. You may define as many parameters and results as you want.

Define Case Study

Check this box to define Case Study data.

Parameters

The table of parameters initially has one row. For information about inserting and removing rows refer to Editing Tabular Data.

Parameter Identifier

The parameter identifier will be used when you define the way you want the output data to be presented after the Case Study has been executed. A default identifier is supplied. To change the parameter identifier, click on it and enter a new identifier.

Parameter

You must identify a parameter to change. Click on parameter to open the Parameter Window where you select the parameter that you want to change. When you return to this window, the parameter will be displayed in place of the original parameter text.

Start Value

Click on base case value to open the Parameter Start Value Window where you define the starting value for the parameter. The starting value defaults to the value of the parameter in the base case. When you return to this window, the starting value will be displayed in place of the original base case value text.

Start Cycle

The start cycle is the cycle at which the start value is used and after which the incremental changes are implemented. Cycles before the start cycle use the value in the base case. To change the start cycle, click on the number (after from cycle) and enter a new value. By default, the starting cycle is one (1).

For “Case Study Matrix,” the Start Cycle field becomes invisible and by default, one (1) is used as the Start Cycle value during the calculations.

End Cycle

The end cycle is the cycle at which the changing ends. Cycles after the end cycle use the value in the end cycle. To change the end cycle, click on the number (after through cycle) and enter a new value. The end cycle defaults to the value of the start cycle.

Note: For Case Study cycle, if same parameter is referred in multiple “parameter identifiers” the cycles should not overlap. Also the parameter identifiers should be entered in ascending order of cycles.

For example- In a case study with 10 cycles when temperature of same stream is different in cycles 1-5 and 6-10, Parameter identifier for Cycle 1 to 5 shall be entered first followed by cycle 6 to 10.

For “Case Study Matrix,” the end cycle value is one (1) by default.

Step Value

When you have selected an end cycle that is greater than the start cycle, you can then define the value of the incremental step change per cycle. Click on 0.00000 to open the Parameter Step Value Window. When you return to this window, the step value will be displayed in place of the original 0.0000 text.

Include or Exclude

A parameter is included in the calculations if its corresponding check box is selected and is excluded from the calculations if it is not.

Results

The table of results initially has one row. For information about inserting and removing rows refer to Editing Tabular Data.

You may define a Result as one flowsheet parameter or as a function of two flowsheet parameters or as a function of one flowsheet parameter and a constant. To enter the second parameter or constant, change the Operator as described below.

Result Identifier

The result identifier will be used when you define the way you want the output data to be presented after the Case Study has been executed. A default identifier is supplied. To change the result identifier, click on it and enter a new identifier.

Operator

To change the format from one flowsheet parameter to a function, click on the operator (an equals sign) and select from the list. The format of the result definition then changes. A second (reference) parameter is displayed and the operator repositions between the first and second parameters. To change the operator again, click on it and select from the list. To revert to the original format with only one parameter, click on the operator and select = (no operator) from the list.

First Parameter

Click on the first (or only) parameter to open the Parameter Window where you select the parameter that you want as a Result or as the first element of the function you are defining. When you return to this Window, the parameter will be displayed in place of the original parameter text.

Second (Reference) Parameter

Click on second parameter to open the Parameter Window where you select the parameter (or constant) that you want as the second element of the function you are defining. When you return to this Window, the parameter will be displayed in place of the original parameter text.

Execution Options

Select from the Execute: list to choose to execute the base case only, or the base case and the case study. If you do not want all the cycles of the case study to be executed, select Base Case and Specified Cycles and then choose a cycle with which to start and a cycle with which to end.

First parameter cycles first

In the Case Study Matrix, by default, the last parameter cycles first, which means the calculation starts at the last parameter. Selecting the “First parameter cycles first” check box reverses the cycle and considers the first parameter first for the calculations.

The "First parameter cycles first" check box becomes available only for the Case Study Matrix. By default, it is clear.

How to get to this Window

This window is opened by selecting the Case Study Data... option from the Input Menu or by pushing $image\CASEICON.gif$ on the Main Window toolbar.

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