switching software/analytics

Dual‑Tracking Checklist: Run Old and New Analytics in Parallel

A rollout plan to validate a new analytics stack before switching off the old one.

Tool Migration Checklist: Web Analytics Provider

Scenario: Migration from Legacy Analytics to New SaaS Provider Audience: SME (Global) | Risk Level: Medium | Timeline: 4-6 Weeks | Team Size: 3-5 (Ops, Marketing, Legal)

Phase 1: Pre-Migration Planning (Week 1-3)

Assessment & Audit

  • Document all existing data points (KPIs, conversion funnels, event triggers).
  • Audit current tag manager containers for redundant or broken triggers.
  • Identify all stakeholders who consume analytics reporting.
  • Create a comprehensive inventory of third-party integrations (CRM, Ad platforms).
  • Review current data retention policies in the legacy tool.

Data Mapping

  • Map legacy event naming conventions to the new provider’s schema.
  • Define custom dimension requirements for the new platform.
  • Document user property attributes (e.g., subscription status, region).
  • Create a cross-reference document for URL parameters and UTM tagging strategies.
  • Map internal IP addresses to be excluded in the new environment.

Golden Copy Backup

  • Export raw historical data in CSV/JSON formats.
  • Ensure all exported reports are stored in a secure, encrypted cloud bucket.
  • Verify the integrity of the exported data (spot-check record counts).
  • Create a "Snapshot" report of top-level metrics (e.g., MoM traffic) for baseline comparison.

Integration Audit

  • Review API rate limits for the new provider.
  • Validate authentication methods (OAuth 2.0, API keys).
  • Test the new tracking snippet in a staging environment.
  • Update Content Security Policy (CSP) headers to allow the new provider’s domain.

Phase 2: Migration Execution

Pre-Cutover

  • Configure user access controls and RBAC permissions.
  • Set up internal data exclusion filters.
  • Configure SMTP relay settings for automated report delivery.
  • Prepare the "Go-Live" communication plan for internal teams.
  • Finalise the data processing agreement (DPA) with the vendor.

Cutover Day

  • Deploy the new tracking code via Tag Manager.
  • Simultaneously disable legacy tracking tags (where applicable).
  • Verify real-time traffic ingestion in the new dashboard.
  • Confirm that session stitching is functioning as expected.
  • Validate cross-domain tracking implementation.
  • Ensure goal conversion tracking is firing on test transactions.
  • Monitor site latency to ensure the new snippet doesn't impact Core Web Vitals.

Verification

  • Perform a 24-hour data parallel run (if possible) to check for discrepancy ratios.
  • Verify that UTM parameters are correctly captured.
  • Check that referral traffic is correctly attributed.
  • Confirm that PII (Personally Identifiable Information) masking is active.
  • Validate custom event triggers against the audit log.

Phase 3: Post-Migration Optimization

Stabilization

  • Re-create critical dashboards for executive stakeholders.
  • Schedule automated weekly/monthly email reporting.
  • Configure alerts for anomalies in traffic spikes or drops.
  • Train team members on the new interface.
  • Document all new internal processes in the company wiki.

Cleanup

  • Decommission legacy tracking accounts to prevent billing overlap.
  • Remove legacy snippets from the source code.
  • Archive the legacy project documentation.
  • Clean up redundant tags in the tag management system.
  • Review access logs to ensure only active users have permissions.

Retrospective

  • Conduct a post-mortem meeting to discuss migration friction points.
  • Review data discrepancy reports against the baseline.
  • Assess the performance of the new tool against the original business requirements.
  • Update the disaster recovery plan to include the new tool.
  • Formalise the "Lessons Learnt" report for future infrastructure projects.

UK GDPR Compliance Checklist

  • Update the Privacy Policy to reflect the new data processor.
  • Implement a granular Cookie Consent banner (GDPR/ePrivacy compliant).
  • Ensure data storage is located within the UK or EU (or verify Standard Contractual Clauses).
  • Configure IP anonymisation settings in the new tool.
  • Establish a process for handling Subject Access Requests (SARs) regarding analytics data.
  • Conduct a Data Protection Impact Assessment (DPIA) if required.
  • Validate that no PII is being captured in URL parameters or event labels.
  • Ensure the vendor provides a clear data deletion policy.

Troubleshooting Common Issues

  • Data Discrepancy: Check for time-zone mismatches between the legacy and new tool.
  • Tag Loading Issues: Inspect the browser console for CSP (Content Security Policy) errors.
  • Missing Referrals: Verify that the "Referrer-Policy" header is correctly configured.
  • Conversion Mismatches: Ensure the "Thank You" page trigger is set to fire once per session.
  • Dashboard Latency: Check if the new tool has a data processing delay (e.g., 24-48 hours).
  • Event Mismatch: Recalibrate the data layer variable names in the new tag container.

Downloadable Resources List

  • Migration Project Timeline Template (Excel)
  • Data Mapping Schema Template (CSV)
  • Stakeholder Communication Email Drafts (Word)
  • Pre-Migration Audit Checklist (PDF)
  • GDPR Compliance Documentation Template (Word)
  • Post-Migration Sign-off Form (PDF)