This article answers the question if an agent who does not answer a call and is then set to "Not Ready - Delivery Timeout" be automatically set back to 'Ready' state.
There is no method to set an agent back to "Ready" state after the agent has been set to "Not Ready - Delivery Timeout". This function has been purposely coded into IPCM to prevent the call from ringing to the same agent again after missing the first call. For example if this feature existed, an infinite loop could occur if there are no other agents available or Ready to take the call, the agent is automatically set to 'Ready' but is not present to answer the call, and the caller does not hangup. The caller's experience could be multiple "ringings" to the same agent without ever being answered.