Enterprise Identity Migration & Application Realignment for £15B UK Telecom Merger

Project Overview

Following a landmark £15B telecommunications merger in the United Kingdom, two massive enterprise workforces needed to unify into a single operational identity structure. Every employee required a synchronized transition: User Principal Name (UPN) updates, email migrations, device collections, and access realignment across approximately 300 business-critical software applications.

Dhimahi Technolabs was engaged as the Lead Solution Architect and Technical Delivery Partner to architect and ship a zero-premium-license, event-driven migration engine on Microsoft 365 and Power Automate, eliminating 180+ manual operational steps, automating communications across 2,745+ user identities, and orchestrating access realignment across ~300 business applications.

The Challenge

Prior to Dhimahi Technolabs’ engagement, this mission-critical programme was drowning in manual operational overhead that threatened multi-week delivery delays and executive escalation.

Core Operational Bottlenecks

• Spreadsheet-Driven Ingestion: Raw batch data arrived in varied CSV formats from disparate IT engineering teams. Operations staff spent hours opening spreadsheets, performing fragile Excel VLOOKUP operations against a master tracker, and manually pasting status updates row-by-row.
• Data Fragmentation & High Error Rates: Incompatible CSV schemas, missing headers, inconsistent date formatting, and duplicate records caused frequent lookup failures, leading to stranded records and operational blind spots.
• Manual Application Realignment & Chasing: When an employee's identity shifted, access to their specific department tools had to be re-provisioned. The migration team manually looked up application assignments, emailed application owners individually, and maintained separate side-spreadsheets to track response SLAs.
• SLA Breaches & Employee Lockout: Without automated escalations, application realignment requests stalled. Migrated employees arrived at work unable to access core billing, network management, or customer service tools.
• Reporting Gridlock: Generating status updates for executive steering committees required manually counting spreadsheet rows and translating figures into static PowerPoint slides, providing data that was outdated before it was presented.

With hundreds of users scheduled per weekly wave, this manual workflow posed acute risks of business disruption across customer care and network operations.

Our Solution & Architecture

Dhimahi Technolabs designed and delivered an automated, event-driven Migration Automation Platform built natively within the client’s existing Microsoft 365 ecosystem. Crucially, the entire architecture was engineered using 100% standard connectors, completely bypassing the multi-thousand-pound recurring licensing costs associated with Power Automate Premium tiers.

Our solution was structured around five core engineering pillars:

1. Autonomous "Drop-and-Done" Ingestion Engine (FL-01)

We created a secure SharePoint drop zone where IT teams simply drop raw batch CSVs. An intelligent ingestion engine automatically detects the batch stage, strips formatting anomalies, auto-maps disparate header schemas, and executes bulk upserts into a centralized Users Master registry in under 3 minutes (down from 4+ hours of manual spreadsheet work).

2. Self-Governing 5-Stage Status Lifecycle (FL-02)

Rather than relying on human judgment, an automated status engine evaluates milestone timestamps (Batch Enabled, Identity Created, Device Handover, Migration Completed) to progress employees seamlessly through the 5-stage lifecycle and trigger appropriate downstream actions.

3. Frictionless 1-Click Work Orders & Communication (FL-03 & FL-04)

The moment an employee's migration completes, tokenized milestone notifications are sent to the user. Simultaneously, interactive work order notifications are dispatched to owners of affected applications. App owners can acknowledge, approve, or flag exceptions with a single click directly from Outlook without logging into third-party portals.

4. Self-Healing SLA Tracking & Late-Stage Onboarding (FL-05, FL-06, FL-07a, FL-08)

A daily autonomous SLA monitor reviews open work orders at 8:00 AM UTC, sending automated reminder notices and escalating prolonged bottlenecks directly to program management. Furthermore, our proprietary Late Application Onboarding engine retroactively generates work orders for already-migrated employees whenever new legacy systems are added to the scope.

5. Live Executive Telemetry & Employee Self-Service (SPFx / React & FL-07b)

Daily 7:00 AM metric aggregations feed live management dashboards embedded into SharePoint Modern Pages. Migrating staff access an SSO-authenticated self-service portal showing their real-time migration stage, scheduled hardware appointments, and active application statuses.

Technical Architecture & Flow Breakdown

| Engine / Component | Architecture / Tech | Operational Function | | :--- | :--- | :--- | | FL-01 Batch Ingestion | SharePoint & Power Automate (Standard) | Ingests raw multi-format CSVs, auto-maps schemas, upserts master registry in <3 min | | FL-02 Lifecycle Engine | Power Automate Recurrence Engine | Automatically calculates and progresses users across the 5-stage migration lifecycle | | FL-03 & FL-04 Comms | Outlook Actionable Messages & HTML Mailers | Tokenized user milestone emails & interactive 1-click work orders to ~300 app owners | | FL-05 & FL-06 SLA Monitor | Daily UTC Automated Cron Flow | Auto-audits application owner turnarounds, sends reminders, escalates breaches | | FL-07a / FL-08 Onboarding | Dynamic Retroactive Scan Engine | Auto-provisions work orders for past waves when new legacy systems enter scope | | FL-07b Telemetry & Portal | React 18, SPFx, TypeScript, Tailwind CSS | Real-time executive BI dashboards and employee self-service migration status tracker |

Results & Measurable Impact

By replacing brittle spreadsheets with enterprise cloud automation, Dhimahi Technolabs turned a high-risk operational roadblock into a streamlined, audited delivery engine:

• 98% Faster Batch Turnaround: Batch ingestion and database reconciliation dropped from 4+ hours of manual VLOOKUPs to under 3 minutes per batch.
• 2,745+ Enterprise Identities Processed: Flawlessly ingested and progressed across 88 distinct historical and live batch files with 0% data corruption.
• ~300 Business Applications Synchronized: Fully tracked and orchestrated access realignment across hundreds of critical telecom systems.
• 100% Elimination of Manual Chasing: Automated 8:00 AM monitors and threshold-based escalation eliminated hundreds of manual email inquiries per week.
• Zero Additional License Costs (£0 Premium Spend): Delivered complete end-to-end automation using native M365 Standard licensing, saving tens of thousands of pounds in recurring process licenses.
• 90%+ Reduction in Support Inquiries: The employee self-service portal provided instant transparency, reducing "What is my migration status?" helpdesk tickets to near zero.

Technical Challenges & Key Learnings

Challenge 1: Incompatible Legacy CSV Schemas

• Obstacle: Legacy files spanned three distinct schema versions—varying from semicolon delimiters and unquoted text to entirely omitted email columns.
• Solution: We engineered an adaptive parser in FL-01 that inspects delimiter signatures, dynamically builds a header-to-index translation map, and executes fallback validation before database commit.

Challenge 2: Cross-Client Interactive Outlook Action Buttons

• Obstacle: Complex adaptive card payloads experienced rendering inconsistencies across older desktop Outlook and web clients.
• Solution: We developed lightweight, cryptographically tagged HTML action links routed into a SharePoint response queue list, guaranteeing universal 1-click execution across all email clients.

Challenge 3: Late Application Onboarding Mid-Flight

• Obstacle: When new enterprise apps were identified weeks into the migration, previously migrated employees risked falling through the cracks.
• Solution: We designed the FL-08 on-demand onboarding engine. With one click, it retroactively scans the Users Master registry, identifies already-completed personnel mapped to the new app, and generates real-time SLA tickets without resetting the user's overall milestone status.

Challenge 4: Overcoming the 5,000-Item SharePoint View Limit

• Obstacle: High transaction volumes in the Application User Mapping list triggered SPQueryThrottledException errors.
• Solution: We enforced indexing on critical foreign keys (EmployeeEmail, AppName_Ref) and refactored client-side dashboard queries to leverage RenderListDataAsStream with stream-level filtering.

Client Testimonial

"Dhimahi Technolabs transformed what was previously an exhausting, spreadsheet-heavy ordeal into an automated, predictable delivery machine. Our operations team went from spending all morning chasing emails and troubleshooting broken lookups to having complete visibility across thousands of users and hundreds of applications. The fact that this was built entirely on our existing Microsoft 365 licensing without added software costs made it an undeniable win for the merger programme."

Huda, Migration Programme Lead, Enterprise Identity Transformation
Tier-1 UK Telecommunications Giant