Enterprise Administration > Windchill Data Loading > Preparing Data for Loading > Data Cleansing: About the Tools Available > Custom Code: Pros and Cons > Cons
  
Cons
Tightly coupled to input and output. A change in the input or output requires a change to the custom code.
No user interface to review the data
Usually requires the use of an additional tool for reviewing data
Multiple skill sets are required
Combination of manual and programmatic efforts, after code is developed