A bank actuary will be able to evaluate customer accounts to determine if those customers are worth keeping.
If a bank customer is frequently overdrawing his account or doesn't keep a certain balance, the bank actuary will make recommendations to the bank. While the bank may or may not be able to close the customer's account, they will treat the customer according to the actuary's evaluation.
For example, if a customer consistently keeps a very low balance in a bank account, the bank could decide to start charging the customer administrative fees if she wants to keep the account open.