Every workflow is assembled from rather small steps, implemented by means of YaST modules written in a YaST-specific scripting language, the YaST Control Language (YCP). These YaST-modules are then called in a predefined sequence to complete a specific task.

In fact it is possible to even write modules in bash and Perl as long as the module need not have a user interface, i.e. it is not interactive. Such non-interactive modules typically handle specific problems like controlling a particular piece of hardware and can be called from within YCP-modules. This building block approach makes constructing complex workflows easy and maintainable.