Choose Models
=============

When you create or modify a case, you must choose the performance and financial model that best describes your project.

.. image:: ../images/SS_ChooseModels.png
   :align: center
   :alt: SS_ChooseModels.png

To choose the performance and financial model:

#. Choose a performance model: In the left column, click the name of the performance model for case. For a description of the models, see :doc:`Performance Models <../introduction/technology_options>`.

When you choose a performance model, SAM displays the all of financial models available for that performance model.

#. Choose a financial model: In the right column, click the name of the financial model. For a description of the financial models, see :doc:`Financial Models <../introduction/fin_overview>`.

#. Click **OK** to create or modify the case.

.. note:: When you change the performance or financial model for a case, SAM populates new variables with default values. Be sure to review the variables on each :doc:`input page <input_pages>` to make sure that they are appropriate for your analysis.

Identifying the Models for a Case
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

When SAM displays the case, you can verify that the performance and financial model are correct on the Main Window:

.. image:: ../images/SS_MainWindow-FinTech.png
   :align: center
   :alt: SS_MainWindow-FinTech.png

.. _changemodel:

Changing a Case's Models
~~~~~~~~~~~~~~~~~~~~~~~~

To change the performance model or financial model for an existing case, on the case's menu, click **Change model**:

.. image:: ../images/SS_CaseMenu-ChangeModel.png
   :align: center
   :alt: SS_CaseMenu-ChangeModel.png