Conversion Cutover and Downtime Planning

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Conversion cutover planning card

• Business downtime = ramp-down + SUM downtime + post-processing + validation + ramp-up.
• SUM with DMO: uptime through Preprocessing; DOWNCONF_DTTRANS starts downtime; Execution migrates and converts.
• Estimate only from mocks on fresh production copies; Planned Downtime Calculator first, measurements after.
• Track planned versus actual per runbook task in SAP Cloud ALM; attack waits and the critical path first.
• Optimize cheapest first; read SAP Note 2351294 per mock; tune DMO with process counts and table duration files.
• Freeze in layers; exceptions only for legal, safety or production-down; retrofit and test every fix.
• Ramp-down: SM02, drain SMQ1/SMQ2/SM58, BTCTRNS1, EWZ5, before picture, verified backup.
• Set go/no-go deadlines from measured fallback time; Contoso: nine hours, latest fallback start Sunday 18:00.
• At each decision: criteria, evidence, contingency left, time to fallback deadline, written confirmations.
• Hand over to hypercare with the runbook log, conditions, open defects and Cloud ALM monitoring in place.