BPMN and flow diagrams, as-is versus to-be analysis, gap analysis, and simple ER and data-mapping work.
3 questions in Business Analysis.
As-is to-be process mapping starts with the process as performed, uses swimlanes to expose handoffs, baselines cycle time and rework, then designs a to-be process that eliminates work before automating it. Use this process modelling answer to show the decision, trade-off, and evidence rather than a memorised definition.
Agree the business meaning and the grain of each entity before touching field names, profile the real data to find the overloaded and sentinel values, then write a mapping where every target field has a source, a rule, a default and a decision for records that cannot be mapped.
Sort the variation by what causes it, because a legal or market difference has to be kept while habit and workarounds should not be. Model a common core with named variants rather than eleven processes or one, and say who loses from each standardisation before you propose it.