I assume, that you are either a business user or an IT department member, with no prior SAP experience, or this is a homework question

You can start by searching for 'variant configuration', I can recommend the Best Practices content on the topic, especially the *.ppt for the scenario overview and the business process documentation as a starting point.

I also read your other question - from what I can see, your best option is to contact a SAP implementation partner and, most likely also a business consulting company. Project scope definition is too important to rely on random people in an internet forum to provide advice, based on limited data.