Abnormal Security Migration: Implementation Plan

Implementation Plan

Do not run this as a vague platform replacement. Run it as a staged migration with explicit validation and rollback points.

Phase	Objective	Status	Notes
Phase 1	Establish architecture baseline: current mail flow, ESA dependencies, stakeholders, and ownership	Planned	Must happen before any claims about cutover simplicity
Phase 2	Confirm Abnormal and M365 integration prerequisites: permissions, tenant approvals, logging paths, remediation model	Planned	Dependency on tenant administrators and security leadership
Phase 3	Define target-state operating model: alert routing, Sentinel visibility, analyst workflow, user-reporting workflow	Planned	Prevents control gaps after ESA removal
Phase 4	Pilot enablement with validation criteria and rollback plan	Planned	Start with low-risk monitoring and evidence collection
Phase 5	Controlled production cutover and ESA decommission plan	Planned	Only after evidence shows parity or improved coverage

Phase

Objective

Status

Notes

Phase 1

Establish architecture baseline: current mail flow, ESA dependencies, stakeholders, and ownership

Planned

Must happen before any claims about cutover simplicity

Phase 2

Confirm Abnormal and M365 integration prerequisites: permissions, tenant approvals, logging paths, remediation model

Planned

Dependency on tenant administrators and security leadership

Phase 3

Define target-state operating model: alert routing, Sentinel visibility, analyst workflow, user-reporting workflow

Planned

Prevents control gaps after ESA removal

Phase 4

Pilot enablement with validation criteria and rollback plan

Planned

Start with low-risk monitoring and evidence collection

Phase 5

Controlled production cutover and ESA decommission plan

Planned

Only after evidence shows parity or improved coverage

Before cutover, validate: