text: From the point of view of an application, consistency means that an auxiliary volume contains 
  the same data as the master volume at the recovery point (the time at which the imaginary 
  power failure occurred). If an application is designed to cope with an unexpected power 
  failure, this assurance of consistency means that the application can use the auxiliary and 
  begin operation as though it was restarted after the hypothetical power failure. Again, 
  maintaining the application write ordering is the key property of consistency. 
  
  For more information about dependent writes, see 11.1.13, “FlashCopy and image mode 
  Volumes” on page 459. 