Correcting before moving.
WHY IT MUST HAPPEN BEFORE MIGRATION
Migrating bad data produces a bad system immediately.
WHAT TO PROFILE
Completeness of required fields Duplicates Invalid values Inconsistent formats Orphaned records
WHAT ORPHANED MEANS
Referencing something that no longer exists.
WHAT TO EXPECT TO FIND
More problems than anticipated.
WHY
Old systems accumulate decades of exceptions.
WHAT TO DECIDE PER PROBLEM
Correct it Exclude the record Accept it, with a rule
WHO SHOULD DECIDE
The business, not the technical team.
WHY
They know which records matter.
WHAT TO PRIORITISE
Data affecting financial accuracy Data preventing operation Data used frequently
WHAT TO DO ABOUT DUPLICATES
Establish matching rules, review matches, and merge with history preserved.
WHAT TO STANDARDISE
Formats: names, addresses, telephone numbers, identifiers.
WHY TELEPHONE NUMBERS SPECIFICALLY
Inconsistent formats prevent matching and messaging.
WHAT TO DOCUMENT
Every cleansing decision.
WHY
Discrepancies are queried afterwards.
WHAT TO PREVENT
The same problems recurring in the new system.
HOW
Validation at entry.
