There are many uses and ways that MAKEMSI could be used, it has been designed to be very flexible.
This section needs more work, I have concentrated on building complete MSI databases from scratch using "uisample.msi" as a template.
Some of these ways or uses are:
Note if you are unsure how to make changes but have a "before" and "after" database you can use MsiDiff.VBS to build the code for you. You can either use as is or tweek to your needs. See "Using ORCA and MSIDIFF to Automate MSI Updates" for more details.
You may also wish to look at the bootstrapper EXE section.