Solution Architecture Practice

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Deprecation Process

Overview

The deprecation process defines how we retire technologies, platforms, APIs, and systems in an orderly fashion while minimizing disruption to the organization. Deprecation is a planned transition that provides teams time to migrate to supported alternatives while maintaining business continuity.

Deprecation Philosophy:

  • Provide adequate transition time (typically 6-12 months minimum)
  • Clear communication of timelines and alternatives
  • Support and resources for migration
  • Gradual reduction of support before EOL
  • No surprises - all deprecations are planned and announced

Deprecation Lifecycle

Decision → Announcement → Transition Period → Support Reduction → End of Life → Sunset

Timeline: 6-18 months from announcement to complete EOL

Phase 1: Deprecation Decision

Duration: 2-4 weeks
Goal: Decide which technologies/systems to deprecate and why

Deprecation Criteria

A technology/system should be deprecated if:

  1. Replacement Available - A better alternative exists
  2. Declining Usage - Fewer than 3 teams use it
  3. Maintenance Burden - Cost > business value
  4. Architectural Misalignment - No longer aligned with strategy
  5. Business Decision - Strategic shift or consolidation initiative

Approval Gate

Who decides: Architecture Review Board (ARB)

Outcomes:

  • ✅ Approved → Move to Phase 2
  • ⚠️ Approved with conditions
  • ❌ Rejected for now

Phase 2: Announcement

Duration: 1-2 weeks
Goal: Announce deprecation to all stakeholders

Announcement Content

  • What’s being deprecated
  • Why it’s being deprecated
  • What replaces it
  • Timeline and milestones
  • Impact assessment
  • Support plan
  • FAQ

Channels

  1. Official Email from VP Architecture
  2. Architecture Forum Q&A session
  3. Wiki/Documentation page
  4. Team one-on-ones
  5. Special notifications for affected teams

Phase 3: Transition Period

Duration: 6-12 months
Goal: Support teams migrating to replacement

Support During Transition

Activity Availability
Bug fixes Critical only
Security patches All
New features None
Migration assistance Full
Training Yes

Migration Planning Per Team

Each team creates migration plan:

  • Current state analysis
  • Target state definition
  • Migration strategy (big-bang/phased/strangler)
  • Timeline with milestones
  • Resource allocation
  • Risk and mitigation planning
  • Testing plan

Migration Checkpoints

  • Week 2: Planning approved
  • Week 4: Design review approved
  • Week 6: Development starts
  • Week 12: Build complete
  • Week 18: Testing complete
  • Week 24: Migration complete
  • Week 26: Stabilization complete

Phase 4: Support Reduction

Duration: 2-4 weeks before EOL
Goal: Transition to minimal support as EOL approaches

Support Timeline

  • 4 weeks before: Critical security only
  • 2 weeks before: No new support
  • 1 week before: Emergency support only
  • EOL Date: Support ends

Extension Requests

If team cannot migrate by EOL:

  1. Request extension (by 2 weeks before EOL)
  2. ARB reviews request
  3. Possible outcomes:
    • ✅ Extension granted (rare)
    • ⚠️ Extension with conditions
    • ❌ Extension denied

Phase 5: End of Life

Duration: 1 day
Goal: Official EOL and system shutdown

EOL Activities

  1. Disable Old System
    • Access restricted (read-only if needed)
    • No new data ingestion
    • Services in maintenance mode
  2. Final Data Archive
    • Backup taken
    • Historical data exported
    • Compliance requirements met
  3. Communication
    • Announcement to organization
    • Users directed to new solution
  4. Infrastructure Cleanup
    • Resources deprovisioned
    • Licenses canceled
    • Contracts ended
  5. Documentation
    • Legacy system marked deprecated
    • Retirement documented

Phase 6: Sunset and Decommissioning

Duration: 1-6 months after EOL
Goal: Complete removal of deprecated technology

Decommissioning Timeline

Activity Timeline Owner
Data cleanup 1 month Data team
Database deletion 3 months Operations
Service shutdown 3 months Infrastructure
License cancellation 3 months Finance
Doc archival 6 months Architecture
Hardware decommission 6 months Infrastructure

Lessons Learned

After decommissioning:

  1. Retrospective meeting
  2. Metrics captured (cost, time, issues)
  3. Lessons learned documentation
  4. Process improvements
  5. Case study created

Special Cases

Critical Systems Deprecation

For widely-used or critical systems:

  • Longer transition period (12-18 months)
  • More communication (monthly forums)
  • More resources (2-3 engineers)
  • Phased deprecation approach
  • Extended support period post-EOL

External Technology Deprecation

When vendor deprecates technology we depend on:

  • Monitor vendor EOL dates
  • Plan migration before vendor EOL
  • Notify users early
  • Use vendor support during transition
  • Escalate to CIO if imminent

Emergency Deprecation

For critical security issues:

  • ARB approves accelerated deprecation
  • 2-4 week transition period
  • Enhanced support during transition
  • Executive communication of urgency

Deprecation Communication Timeline

Example 12-month deprecation:

Month Action Communication
1 Decision & approval Internal ARB decision
1.5 Official announcement All-hands email + forums
2 Resources ready Documentation published
3 First checkpoint Status reporting begins
5 Halfway Progress report to leadership
7 Support reduction Limited support notification
9 EOL date Final reminders
9 System deactivated Old system shutdown
12 Decommissioning Lessons learned documented

Status: Complete
Last Updated: November 2025
Version: 1.0
Owner: VP Architecture