Overview
An Australian engineering and construction organisation partnered with Arinco to support its strategic transformation program focused on consolidating multiple independently operated technology environments into a unified Microsoft platform supporting over 14,000 users and guest accounts and over 80 enterprise applications across the organisation. As the organisation continued to centralise business functions and simplify operations across its multiple technology environments, there was a need to modernise fragmented identity, collaboration and operational environments while maintaining continuity for existing business-critical systems.
Arinco designed and delivered a new greenfield Azure, Microsoft 365 and Entra ID environment, alongside large-scale migration, coexistence and governance capabilities that enabled progressive transition with minimal disruption. The program established a scalable, cloud-first foundation that improved operational consistency, strengthened governance and supported ongoing enterprise transformation.
Business challenge
The company operated across multiple independently managed technology environments, each with its own Microsoft 365 tenant, Active Directory environment, device management standards, collaboration platforms and operational processes. Over time, this fragmented environment created increasing complexity for both users and technology teams. Employees often required multiple identities or devices to perform their role, while support teams were required to manage differing security controls, operational processes, application packaging approaches and cross-tenant collaboration models.
As the organisation continued to centralise business functions and simplify how teams operated, there was a need to consolidate the underlying technology landscape and create a more consistent platform for identity, collaboration, security and operations.
The objective was to consolidate these environments into a single modern Microsoft ecosystem that would simplify operations, strengthen governance and create a more consistent user experience across the organisation. The solution also needed to support thousands of users, multiple operating environments, existing business-critical applications, legacy on-premises systems and ongoing operational requirements, while enabling the organisation to transition towards a modern cloud-first platform.
Solution
Arinco worked with the organisation to design, build and migrate the future-state Microsoft environment underpinning the transformation initiative, establishing a unified platform for identity, collaboration, governance and operations across the organisation.
Working closely with stakeholders across infrastructure, security, operations, applications, vendors and project leadership, Arinco helped to shape the migration roadmap, define governance patterns and deliver the future-state platform architecture. The engagement included architecture workshops, technical validation, migration planning and operational readiness activities across identity, collaboration and Azure platform services.
Designing the future-state platform
Arinco designed a new greenfield Azure, Microsoft 365 and Entra ID environment aligned to cloud-first and secure-by-design principles. The platform provided a consistent foundation for identity, collaboration, governance and security across the organisation, while allowing existing systems and operating companies to continue functioning during migration activities.
The architecture covered Azure platform foundations, Microsoft 365, Entra ID, Active Directory Domain Services integration, Entra ID Connect configuration, DNS architecture and cross-tenant access models. The solution balanced long-term modernisation goals with operational continuity, enabling the adoption of cloud-native services while preserving access to legacy applications, on-premises systems and existing business-critical environments.
Establishing identity and coexistence foundations
Arinco designed and implemented the identity architecture required to support the single modern Microsoft ecosystem while enabling coexistence with existing operating environments.
This included hybrid identity models, Active Directory trust relationships, Entra ID Connect and cross-tenant synchronisation and guest access models that allowed users in the new environment to continue accessing services hosted within existing company tenants.
This progressive migration approach reduced disruption by enabling workloads, applications and operational teams to transition incrementally rather than requiring all systems to move simultaneously.
Building the Microsoft 365 collaboration platform
Arinco also designed and configured Microsoft 365 collaboration services including Exchange Online, Microsoft Teams, SharePoint Online, OneDrive, Power Platform and Power BI. Governance and lifecycle management controls were implemented to improve collaboration consistency, operational maintainability and security across the environment.
As part of the transformation, Arinco supported the migration and consolidation of more than 700 Microsoft Teams environments, 300 SharePoint sites and nearly 90TB of Teams and SharePoint data. Power Platform and analytics workloads including Power Apps, Power Automate and Power BI were also transitioned as part of the broader modernisation program.
Delivering migration and transformation activities
Arinco worked alongside the organisation’s project, operational and business teams to deliver migration activities across users, workloads, applications, collaboration platforms, intranet services and Power BI environments.
More than 80 enterprise applications were integrated or transitioned as part of the program, including identity integrations, authentication changes, SSO configuration and coexistence requirements designed to maintain continuity throughout the migration process.
Comprehensive testing and readiness activities were undertaken to minimise disruption, including migration validation, user readiness planning, operational testing, support preparation and cutover coordination. During migration weekends and production cutovers, Arinco engineers worked closely with stakeholders to support execution, issue resolution and post-migration support and hypercare activities.
The transformation included the migration of over 14,000 users and guest accounts, over 5,400 mailboxes containing more than 100TB of data and approximately 140 million mail items, as well as more than 1,500 shared mailboxes and 1,000 meeting room mailboxes.
Outcomes
The transformation initiative established a modern Microsoft platform capable of supporting long-term operational simplification, improved collaboration and future growth across the organisation. By consolidating fragmented environments into a unified ecosystem, the organisation improved consistency across operating companies while reducing operational complexity for both users and technology teams.
Key outcomes included:
- Unified Microsoft platform: Established a greenfield Azure, Microsoft 365 and Entra ID environment supporting ongoing consolidation across the organisation.
- Large-scale enterprise migration: Successfully migrated over 14,000 users and guest accounts and over 80 enterprise applications across multiple operating environments.
- Modernised identity and access: Implemented hybrid identity and coexistence models that supported secure access across legacy and future-state environments while reducing disruption during transition activities.
- Improved collaboration experience: Consolidated more than 700 Microsoft Teams environments, 300 SharePoint sites and nearly 90TB of Teams and SharePoint data into a more consistent collaboration platform.
- Successful mailbox transformation: Migrated more than 5,400 mailboxes containing over 100TB of data and approximately 140 million mail items, alongside more than 1,500 shared mailboxes and 1,100 meeting room mailboxes.
- Reduced operational complexity: Improved consistency across operating companies by aligning identity, collaboration, governance and operational platform standards.
- Enhanced governance and maintainability: Established standardised governance, lifecycle management and collaboration controls across Microsoft 365, identity and Azure platform services.
- Maintained operational continuity and reduced user disruption: Preserved access to legacy applications, collaboration services and business-critical systems through carefully designed coexistence and migration strategies.
- Scalable foundation for future transformation: Created a repeatable migration and governance model capable of supporting future operating company migrations and broader enterprise modernisation initiatives.
What's next?
Following the successful completion of the initial migration phases, Arinco is continuing to support the ongoing rollout of the transformation initiative across additional operating companies and workloads.
The program continues to build on the foundations established through the platform design, identity architecture, governance alignment and migration activities, supporting long-term strategy for operational consistency, enterprise collaboration and cloud modernisation.
