Salesforce: Points to consider while data migration

Step 1:-  Working on Source

• Define the scope of migration i.e. which objects and fields needs be migrated. For ex. not all objects, field and records needs to be in target system. for ex. we may need data of only past 2 years 
• Check the ER of source data and find master detail / parent child relationships 
• For auditing purpose we should take full backup but it should be different from migration backup
• Take the down time and sure no one can modify data while we are performing migration.

Step 2:- Working on staging DB

• Perform all data clean up in staging DB
• If any calculations/data massaging needs to be done, then that should also be done in staging. It will remove the load on target system when you load data in bulk.
• Use VLOOKUP to maintain referential integrity
• Security of data 
• Duration of backup process - data may chnaged while running backup process. 

Step 3:- Test data load in Full Copy Sandbox

• We should test data load in sandbox environment.  
• Disable all unnecessary activities i.e. triggers, validation rules, workflow, assignment rules   
• Make sure minimum to sharing calculations are happening
• Decide which API suites you best i.e SOAP, Bulk with serial mode, Bulk with parallel mode
• Arrange data in a way to reduce locking at target system
• We will need to create external id fields in target system to preserve the relation ships.
• Prepare check list / To do list based on challenges you face that you can use for actual data migration in production. 

Step 4:- Actual data load

• We will get lot of learning while testing in sandbox. We need to apply all that in production follow the check list. 
• Run reports and queries to check the statistic make sure they match 
• Do some sample checks 
• Enable triggers, validation rules, workflow, assignment rules
• Update sharing model to meet your business needs and recalculate sharing 
• After migration run both system in parallel. Don’t immediately discard source system. Keep a limited access to source system