A Global Automotive Technology Company Completes Microsoft 365 Tenant to Tenant Migration Following Divestiture Acquisition

The Challenges 

Migration of a global tenant of this scale introduced a range of interconnected challenges that had to be addressed to ensure a smooth transition. Beyond the sheer volume of data and users involved, the project required balancing business continuity, data integrity, and user experience across multiple Microsoft 365 workloads. The following challenges outline the key areas that shaped the migration strategy and execution approach. 

Scale of User Migration 

A tenant migration involving approximately 7,000 users while ensuring zero disruption to daily business operations posed a significant coordination challenge, requiring careful sequencing, communication, and support planning across a large, active user base. 

Massive Data Volumes 

The migration involved transferring over 150 TB of Exchange Online mailbox data (across ~7,000 user mailboxes and up to 810 shared mailboxes) and roughly 130–135 TB of OneDrive for Business content. Moving this volume of data without loss, corruption, or extended downtime demanded robust throttling management, bandwidth planning, and validation processes. 

Complexity of Collaboration Content 

Thousands of SharePoint Online sites (approximately 4,700–7,600, up to ~26 TB) and nearly 2,900 Microsoft Teams workspaces including channel conversations, needed to be migrated while preserving site structures, granular permissions, and ongoing collaboration continuity. Associated content such as Whiteboards linked to Teams and OneDrive added further complexity to maintaining a consistent user experience post-migration. 

Phased Cutover Requirements 

The business required a prioritized, risk-managed cutover approach, with a critical subset of approximately 700 business service users migrated ahead of the broader population. This phased strategy was needed to validate migration processes and minimize business risk before scaling to the full user base. 

Change Management Across a Global Workforce 

With users distributed globally, driving adoption, delivering effective communications and training, and providing post-migration stabilization support presented challenges in ensuring consistent readiness, minimizing helpdesk escalations, and sustaining productivity throughout the transition. 

Decentralized/Self-Service Workloads 

Certain content types, such as Microsoft Forms, could not be migrated through standard tooling and relied on user-driven, self-service migration requiring clear documentation and guidance to ensure completeness and reduce data loss risk. 

The Solution 

Netwoven addressed these challenges through a structured, phased migration approach designed to minimize business disruption while ensuring data integrity, security, and a smooth user experience throughout the transition. 

Migration Planning 

The engagement began with a Project Initiation phase, during which Netwoven established the foundational elements for a well-governed migration. This included onboarding into the customer's environment, provisioning necessary access, validating infrastructure readiness, and setting up project governance frameworks. A collaborative workspace was created to enable transparent communication between teams, supported by a detailed project plan and schedule that aligned technical execution with business priorities. 

Building on this foundation, the Detailed Planning and Assessment phase focused on gaining a comprehensive understanding of the environment prior to migration. Netwoven conducted a full inventory of mailboxes, OneDrives, SharePoint sites, and Teams workspaces, followed by migration readiness reviews to identify potential risks and dependencies. Dedicated architecture workshops helped define the technical approach, while coexistence planning ensured users could continue working seamlessly across both environments during the transition. This phase concluded with prioritization and mapping activities in a tenant-to-tenant migration checklist that informed a logical, risk-managed sequencing of the migration. 

Tools Setup and Proof of Concept 

To validate the approach before scaling, Netwoven executed a Proof of Concept Migration. The tools such as Quest ODM and ShareGate were set up appropriately to migrate chosen workloads. Initial AD configuration was done to decouple end-user devices, identity, and SSO applications and site migration from content migration. AD accounts staging and account sync were also undertaken. A select set of 20 users covering different geographies were migrated as pilot users. Finally, a representative sample of up to 20 mailboxes, 20 OneDrives, and 20 SharePoint sites and Teams were migrated. The whole activity was completed in about a month. This controlled pilot allowed the team to test migration tooling, processes, and timelines in a real-world setting, with user acceptance testing and validation confirming readiness before proceeding to full-scale migration - reducing risk and building organizational confidence in the process. 

Production Migration 

With the approach validated, Netwoven moved into Production Migration, executing bulk migration of Exchange Online mailboxes, OneDrive content, SharePoint Online sites, and Microsoft Teams - including channel conversations and associated Whiteboards.  

All M365 productivity Workloads were migrated at the same time (Email, OneDrive, SharePoint and Teams) using Quest Tool and ShareGate in the following fashion with archiving after Primary Email migration. 

• Bulk Migration of Email (Quest ODM) – 150 TB @ 1.5TB/day @6days a week for 17 weeks for 7K users followed by Delta migration and Hypercare support
• Archive Data Migration (Quest ODM)
• Bulk Migration OneDrive (Quest ODM) OneDrive – 120 TB @ 3TB/day @6days a week = 8 weeks)
• Bulk SharePoint & Teams (ShareGate) migration – 7K Users

Each migration wave was followed by structured user validation and sign-off processes, ensuring that content, permissions, and collaboration capabilities were accurately preserved, and business teams could confirm successful transition before moving forward. 

Adoption and Change Management (ACM) 

Recognizing that a successful migration extends beyond the technical transfer of data, 

Netwoven placed strong emphasis on Adoption and Change Management to support long-term user readiness and business continuity. The important ACM activities were:

• Tailored communication and training content development
• Helpdesk knowledge transfer
• User cutover guidance
• Open office-hour support sessions
• Hypercare support following each migration wave
• User guidance for managing multiple browser profiles during coexistence and transition periods  

Together, this end-to-end methodology enabled Netwoven to deliver a secure, well-governed migration in 5 months that balanced technical rigor with user-centric change management - ensuring business continuity, data integrity, and sustained adoption across a globally distributed workforce. 

Business Benefits 

The successful migration project yielded the following benefits. 

• Unified Collaboration Environment
  Consolidated Microsoft 365 workloads under a single tenant, unifying user experience, improving governance, security, and collaboration.
• Operational Continuity & User Satisfaction
  Seamless cutovers and phased migrations ensured uninterrupted operations and positive user experience.
• Improved Compliance & Access Control
  Streamlined identity management and access policies reduced compliance risks and administrative overhead.
• Scalable Infrastructure for Future Growth
  Infrastructure provisioning and tooling setup supported high-throughput migrations and future scalability.