How long does a cloud migration take?

Vendors will tell you cloud migration is quick and easy. The reality is more nuanced. Let’s set realistic expectations.

The Honest Timelines

Here’s what we actually see for well-planned migrations:

Company Size	Simple Migration	Complex Migration
10-25 employees	4-8 weeks	2-3 months
25-50 employees	6-12 weeks	3-4 months
50-100 employees	2-4 months	4-6 months
100-250 employees	3-6 months	6-12 months

Simple: Mostly standard applications, good documentation, cooperative users Complex: Custom applications, compliance requirements, legacy systems, multiple locations

The Four Phases of Migration

Phase 1: Discovery and Planning (2-4 weeks)

What happens:

• Inventory all systems and applications
• Document current configurations
• Identify dependencies
• Assess cloud readiness
• Develop migration strategy
• Create project plan
• Estimate costs

Why it takes time:

• Finding undocumented systems
• Understanding application dependencies
• Getting stakeholder buy-in
• Proper planning prevents problems

Shortcut temptation: Skip planning and just start migrating. Reality: This causes 90% of migration problems.

Phase 2: Preparation (1-4 weeks)

What happens:

• Set up cloud environment
• Configure networking and security
• Establish backup and recovery
• Prepare migration tools
• Create test environment
• Train staff on new tools

Why it takes time:

• Proper security configuration isn’t instant
• Network connectivity requires testing
• Compliance requirements need verification
• People need training before cutover

Phase 3: Migration Execution (2-8 weeks)

What happens:

• Migrate data and applications
• Test each migrated component
• Validate functionality
• Address issues as they arise
• User acceptance testing
• Cutover planning

Why it takes time:

• Data transfer speed limitations
• Application-specific configurations
• Testing takes time
• Issues discovered during testing
• User training and support

Migration approaches:

Big bang: Everything moves at once over a weekend

• Faster overall timeline
• Higher risk
• Requires extensive preparation
• Best for smaller, simpler environments

Phased: Move systems in groups over weeks

• Lower risk
• Longer timeline
• Easier to manage
• Better for complex environments

Phase 4: Stabilization (2-4 weeks)

What happens:

• Monitor new environment closely
• Resolve post-migration issues
• Optimize configurations
• Finalize documentation
• Close out old systems
• Knowledge transfer

Why it matters:

• Issues emerge under real load
• Users need support adjusting
• Performance tuning required
• Old systems need proper decommissioning

What Causes Delays

Technical Delays

Application compatibility: “This app doesn’t work in the cloud” - discovered mid-migration. Solutions take time.

Data volume: Migrating 10TB over a business internet connection? Do the math. It takes days or weeks.

Network issues: Latency, bandwidth, routing problems between on-premise and cloud.

Unexpected dependencies: System A requires System B, which requires System C. Sequence matters.

People Delays

Decision paralysis: Stakeholders can’t agree on approach, timing, or priorities.

Unavailable resources: Key person on vacation, competing projects, not enough IT staff.

Resistance to change: Users don’t want to learn new tools. Adoption is slow.

Incomplete requirements: “Oh, we also need X” - discovered mid-project.

Business Delays

Compliance review: Legal or compliance needs to approve cloud configurations.

Budget approval: Costs come in higher than expected. Need additional approval.

Business events: Month-end close, tax season, product launches - can’t disrupt operations.

Vendor dependencies: Waiting on software vendors for cloud compatibility or licensing.

How to Keep Your Migration on Track

Before You Start

1. Document everything - You can’t migrate what you don’t know about
2. Set realistic expectations - Add 25-50% buffer to initial estimates
3. Get executive sponsorship - Removes blockers faster
4. Involve stakeholders early - Fewer surprises later

During Migration

1. Test before cutover - Never skip testing to save time
2. Communicate constantly - Users should never be surprised
3. Have rollback plans - Know how to undo if needed
4. Track issues rigorously - Don’t let problems slip

After Migration

1. Don’t abandon old systems immediately - Keep them available for reference
2. Plan for optimization - First migration isn’t final state
3. Gather feedback - Users will find issues you didn’t
4. Document learnings - For next time

The “Quick Migration” Myth

Why vendors underestimate:

• They want to close the sale
• They assume best-case scenarios
• They don’t include planning and stabilization
• They’ve never done YOUR migration

What “2-week migration” usually means:

• Just the data transfer
• Not including planning or testing
• Not including training or stabilization
• Assuming everything goes perfectly

What actually takes 2 weeks:

• Very small businesses (under 10 people)
• Pure SaaS migration (nothing custom)
• No compliance requirements
• Perfect preparation

Real-World Example Timelines

Scenario 1: 25-Person Office Moving Email to Microsoft 365

Total time: 4-6 weeks

• Planning: 1 week
• Preparation: 1 week
• Migration: 1-2 weeks (mailboxes migrate overnight, but staggered)
• Stabilization: 1-2 weeks

Scenario 2: 50-Person Company Full Cloud Migration

Total time: 3-4 months

• Planning: 2-3 weeks
• Preparation: 2-3 weeks
• Migration: 6-8 weeks (phased)
• Stabilization: 3-4 weeks

Scenario 3: 100-Person Healthcare Company (HIPAA)

Total time: 5-7 months

• Planning: 4-6 weeks (compliance review takes time)
• Preparation: 3-4 weeks
• Migration: 8-12 weeks (extra testing required)
• Stabilization: 4-6 weeks
• Compliance verification: Throughout

Questions to Ask Your Migration Partner

1. What’s included in the timeline? All four phases?
2. What assumptions are you making? Best case or realistic?
3. What could extend the timeline? What are the risks?
4. What’s the rollback plan? If things go wrong?
5. Who’s responsible for what? Your team vs. theirs?
6. What does “done” look like? Clear completion criteria?

The Bottom Line

Plan for migrations to take longer than initial estimates. Build in buffer time. Don’t schedule cutover the week before a critical business event.

A well-planned migration that takes 3 months is infinitely better than a rushed migration that creates months of problems.

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Planning a cloud migration? Contact us for a realistic assessment and timeline based on your specific environment.