what are the major system values that used to check & change regularlly in an organisation
That’s up to your organization. However, none of them should be ‘changed’ regularly. If any need regular changes, something is probably wrong with the organization.
Read the Security section of the Information Center.
You should understand that this is not a training site. This site can help solve problems, but no one is likely to spend their time giving free training when all of the information is already available in the Information Centers from IBM.
usually once system values have been set, they will not be change any time that they want. by changing the system values it might impact your system application or how the way u will do your work.