The systems life cycle

The systems life cycle

1. Verification

   • Definition
     • A way of preventing errors when data is input
   • Ways of verifaction
     • Double entry
       • Data is entered twice
     • Visual check
       • The person entering data must check for errors

2. Validation

   • Definition
     • A way to reduce errors
   • Types of validation
     • Presence check
       • Makes sure that a field is not left blank
     • Range check
       • Ensure data is in defined range
     • Type check
       • Ensures correct type of data is entered
     • Length check
     • Format check
     • Check digit
       • Works with an algorithm