Based on multiple time and attendance migrations, here’s my comprehensive perspective on the key focus areas:
Data Mapping Strategy: The critical decision is determining what constitutes “required” versus “nice to have” historical data. For regulatory compliance, you need enough history to demonstrate adherence to FMLA, state leave laws, and collective bargaining agreements - typically 2-3 years. For operational purposes, current balances plus 1 year of transactions usually suffices. Map your source time off types to Workday time off types carefully - differences in accrual frequencies, carryover rules, or caps will cause balance discrepancies. Create a detailed mapping document that shows how each source time type converts to Workday, including any business rule changes. For time entry history, consider migrating only exception-based entries (absences, overtime) rather than every regular hour worked - this reduces volume significantly while preserving audit trail.
Validation Approach: Implement validation at three levels. First, validate source data completeness and quality before extraction - identify employees with negative balances, missing accrual rates, or orphaned transactions. Second, validate reference data resolution during transformation - every time off type, worker ID, and position must resolve to valid Workday references. Third, validate results post-load through reconciliation reports. Build automated balance reconciliation comparing source system to Workday by employee, time off type, and balance date. For transaction history, validate that transaction counts and hour totals match between systems. Set tolerance thresholds - we used 4 hours variance as acceptable given rounding differences in accrual calculations. Any variance beyond tolerance requires root cause analysis and correction before proceeding.
Historical Data Considerations: Older data presents unique challenges. Time off plans may have changed multiple times - different accrual rates, carryover rules, or caps. Document these changes and decide whether to migrate with original plan rules or adjust to current configuration. For employees who transferred between locations or changed eligibility status, their time off history may span multiple plan assignments. Consider consolidating to their current plan for simplicity, but preserve original transaction dates for audit purposes. Historical data quality issues are common - duplicate transactions, manual adjustment entries without documentation, or balance corrections that weren’t properly recorded. Build exception handling into your Studio integration to flag these anomalies for manual review rather than loading bad data into Workday.
One often-overlooked aspect: coordinate with payroll on the cutoff strategy. If you migrate mid-pay-period, you’ll need to handle partial period accruals carefully to avoid double-accruing or missing accruals. We recommend migrating at pay period boundaries to simplify reconciliation.
Finally, don’t underestimate the effort required for validation and reconciliation. Plan for 40-50% of your migration timeline to be dedicated to data quality activities rather than just the technical load process.