“We're replacing this system — what does it touch?”
Every migration discovers dependencies the hard way, usually mid-project. Trace the system through the model first and the blast radius is known before the RFP, not during cutover weekend.
Downstream systems that read its data, workflow steps that would stall, and the data it is source-of-record for.
A scoped change plan with dependencies, risks, and sequence known up front.
Replacing the SIS looks like one project until the model shows a dozen systems read enrolment data from it and five workflows route through it. The cutover plan now accounts for all of them, instead of finding the last one in production.