Over and above what Mr. Umakanthan M has been explained, I would like to add that there is list of jobs( exhaustive) attached to Wage Code Central Rule which my help to find out the job skill.
There may be other methods as follows:-
1. Determination of job skill instead of employee skill and the person engaged in the same job will be accordingly in that category - USK, SSK, SK or HSK. There are experts available in the market who will go in to the details of the of the jobs to identify its skill differentiation.
2. In majority organizations, contract labours are engaged with similar nature of jobs with the permanent people . If there is already skill differentiation of permanent employees, the contract labour will be in the same skill category accordingly.
S K Bandyopadhyy ( Howrah, WB)
CEO-USD HR Solutions
www.usdhrs.in