Case Studies

About Case Studies

A Case Study allows you to systematically modify the values of variables or parameters to determine how those changes affect the simulation. That is, it allows you to analyze and understand the relationship between certain design variables and the observed process performance.

A Case Study consists of a set of test cases, one for each combination of initial values and step changes in the manipulated variables and parameters. During a Case Study run, the software re-solves the simulation for each case. At the end of the Case Study run, the simulation remains at the values from the last case in the Case Study.

Important: Because the simulation retains the values from the last case in a Case Study, we highly recommend that you capture a snapshot of your simulation before you run any Case Studies.

You can generate a plot of the case data to visualize the effects of your variable or parameter changes on the simulation.

You can use Case Studies for numerous, far-reaching applications, including but not limited to:

• Developing a robust engineering design.

• Creating controller design studies.

• Performing simple optimization by enumerating the available options.

• Validating the thermodynamics of the system.

Concepts

• Use the Case Study Manager to create and manage your Case Studies.

• Use the Case Study Editor to configure your Case Studies. You can access the Case Study Editor from the Case Study Manager.

• You can run a Case Study only in Process or Fluid Flow mode.

• You can add as many variables and parameters to a Case Study as needed. This includes:

  • The variables and parameters that you want to change (manipulated variables and parameters).

  • The variables for which you want to see the effects of those changes (observed variables).

• You can add only Real or Integer parameters to a Case Study.

• A Case Study must have at least one manipulated variable or parameter and one calculated variable or parameter to run.

• You can manipulate up to two variables and parameters at a time in the following combinations:

  • Two variables

  • One variable and one parameter

  • Two parameters

• For each manipulated variable or parameter, you must set the minimum value, maximum value, and number of steps to define the different cases in the Case Study.

• The software automatically calculates the step change value after you set the minimum value, maximum value, and number of steps for each manipulated variable or parameter. You cannot change this value.

• The units of measure (UOMs) in the Case Study Editor always match those in the simulation. If you want to change the UOMs for a Case Study, you must change them in the simulation.

• Depending on the size of your simulation and the number of cases in your Case Study, you may have to wait a significant amount of time for your Case Study run to complete. See Number of Cases and Performance for more information.

• You can set the snapshot that you want to revert the simulation to if a case in the Case Study fails to solve.

• The Case Study retains case data for both failed and successful solves so that you can see the variable and parameter values that the solver struggles with.

• The order of the variables and parameters in the Case Study determines which variable or parameter the software manipulates first. See Reorder variables and parameters in a Case Study for more information.

• After a Case Study run, the simulation remains at the values from the last case in the Case Study.

• After you run a Case Study, you can generate a plot for the case data to visualize the effects of the changes in the manipulated variables or parameters.

• The Case Study plot remembers your plot configuration settings so that you don't have to reconfigure the plot every time you open it.

Actions

• Create a Case Study.

• Rename a Case Study.

• Add variables and parameters to a Case Study.

• Set up to two variables or parameters as manipulated values for each Case Study.

• Define each case in a Case Study by entering the minimum value, maximum value, and number of steps for the manipulated variables or parameters.

• Run a Case Study.

• Stop a Case Study run if it takes too long to complete.

• Copy the Case Study results and paste them into a table or spreadsheet in another software program, such as Microsoft Excel.

• Generate a plot for the result data in a Case Study.

• Manually return the simulation to the initial starting point before you ran a Case Study.