The following workflow is an example to illustrate the steps required to create a Parametric Cell using Constraints, Variables, Variations and its placement.
In this example we will create a simple 3D door leaf with an opening as a Parametric Cell, such that when a designer places the Parametric Cell they are able to choose between different types (Variations) as well as modify sizes (Variable values) as required.
This example is not intended to provide the full steps or a detailed design and it is expected a general knowledge of MicroStation and the design intent/detail is known by the designer. Further information on the tools can be found in the help and learn material.
http://communities.bentley.com/products/microstation/w/microstation__wiki/30263.how-can-i-edit-the-variables-in-parametric-cells
http://communities.bentley.com/products/microstation/w/microstation__wiki/24880.how-to-create-a-parametrci-profile-creating-and-assigning-variables
http://communities.bentley.com/products/microstation/w/microstation__wiki/24876.how-to-create-a-parametric-profile-creating-and-assigning-constraints
http://communities.bentley.com/products/microstation/w/microstation__wiki/26616.how-to-export-the-variations-of-parametric-cells-into-a-csv-file