I’ve written many times about managing exceptions and being careful not to design rules around exceptions. As a general rule of thumb, if a given action occurs less than 10% of the time, it’s an exception, and should be treated as such.
For example, one of the most common complaints I hear from my clients is that members and customers will create duplicate records. They go to the website, can’t remember their login, and rather than using the “forgot password” functionality, they create a new record.
The first question I always ask is “How often does this happen?” Because the reality is, some percentage of customers are always going to ignore the forgot password, or create multiple records in order to “cheat,” or do something else that most customers don’t do. That’s the reality.
What we need to ask is, how often does this happen? Because even though these things are remarkably irritating to staff, they are probably rare compared to the number of customers who actually DO remember their password!
You will always have duplicate records. You will always have customers who are too lazy (or too dumb??) to use the forgot password functionality. Don’t let these typically very small exceptions drive your business rules.