Induction referred to formal training programs that an employee had to complete before they could start work
Orientation was the informal information giving that made the recruit aware of the comfort issues – where the facilities are, what time lunch is and so forth.How long should the induction process take?
It starts when the job ad is written, continues through the selection process and is not complete until the new team member is comfortable as a full contributor to the organization’s goals.
The first hour on day one is a critical component – signing on, issuing keys and passwords, explaining no go zones, emergency procedures, meeting the people that you will interact with all have to be done immediately. Until they are done the newcomer is on the payroll, but is not employed.
After that it is a matter of just in time training – expanding the content as new duties are undertaken.
You can refere
Core Human Resources for more information