Online Banking continue to work just fine whether you decide to activate PIB or not.  You should not activate PIB without some careful planning and preparation.  You need a plan.  A plan for marketing the change to members.  A plan to train your staff.  A plan for rolling out the changes with an acceptable level of disruption to members and staff.  A plan to handle the increase in phone calls and frustrated members.  A plan to make this part of your process for opening new memberships.  A plan for ongoing marketing and reinforcement. 

Remember that if your risk assessment indicates that no new authentication methods are needed right now, you can spend some time deciding whether PIB is right for you, then flip the switch when the time is right.