Importance of pre-production like environment

Pre-production environment plays pivotal role in defining test completion criteria. System Performance and System Readiness testing rely on a stable system like Production - called Pre-prod environment. These tests are final preparation for the new system and will dictate whether the Production environment is ready for actual production processing.  In terms of completion criteria, both phases are all or nothing.  This means, in both phases, tests either pass or fail as a whole based on pre-determined criteria from Business Users, Legacy Owners, and Process Owners.  

The precautions an organization should take place:

• Entire infrastructure or architecture should be as close as production
• Various kinds of testing to be preformed
• Accounts to be used against these enviornments
• Revenue impacts
• Automated testing if any, which test scenarios to be executed
  
  
  

Since these environment is very close to real production environment, tons of weired behavior of application or product can be detected early on in release cycle in help avoiding last minutes or production emergencies.

However, one should not perform entire testing on these environments. Say a day or 2 days execution of various tests is good enough!