Hi Anju,
We have the same group and level method to classify EEs based on importance of job. For example company specifies job A is most important of job B then they assign a high start of group to job B than job A. In a job B again we have levels which EE will take based on their experince. For example each year and EE can move a level of if s/he moved to last level of a group will move a group and so on.
I didn't get you last part of question about TARIF and its valiants. If you mean what they mean you have it in vaiants' descriptions. For example to get value for a WT from T510 you have to put module vaiant for WT in V_T511 as B.
Regards,
Omid