Problem:
Interest calculations are incorrect and too high for some customers. Presumably they worked some years before, but the Customer Service Manager did not know when the problem started.
Why it mattered:
Customers do not want to be overcharged.
Characters:
- Customer Service Manager
- IT Manager
- Accounting Manager
Attempts at resolution:
First: to find out when the problem started by going back to 2008 when it calculations worked. Writing programs to analyze the billing data for specific customers to identify year and month when the calculations went wrong, finding when a change in pattern started. Second : identify the programs that were calculating the interest.
Solution:
Finding time of change and programs lead to the discovery that changes had been made to the programs to accommodate other issues. Talking to the parties involved in the various changes resolved different interpretations of how the interest was to be calculated in different situations.
Summary:
Fixing a problem for one stakeholder sometimes introduces problems for another stakeholder. Data analysis can usually pinpoint the timeframe when a change started. In this case AR and Sales had different opinions about interest calculation.