Need to make EPS ID ; any problem? what is its purpose?

Can contact  if it is needed to make EPS ID or faced any problem in it.

Procedure 
Current Progress
Date(YYYYMMDD)
EPS-TOPIK Pass(92)2015-09-19
Job Seekers Roster Forwarding DateSend2015-12-06
Job Seekers Roster Approval DateApproval2015-12-22
* Term of Roster Validity :
2015-12-22~2016-12-20
Employment Permit Issuance
Issued2016-02-22
Standard Labor Contract Forwarding
Contract Transferred2016-02-25
Standard Labor Contract Signing
Signed2016-02-28
CCVI Issuance
Issued2016-04-01
Tentative Entry Date-2016-04-25
Actual Entry Date
(To be announced by Sending Agency)-2016-04-27
Employment TrainingCompleted2016-04-29
Assigned to Work-2016-04-29) .
EPS ID is required upto the arival of Korea in order to get all the informations .So keep it safely.