Analyzing time depends on the quantity of files on your device. The more files your device has, the longer time it will take to analyze your device. If you encounter this situation, you can refer to following tips:
1) Unlock the device if there is Screen Lock password.
2) Make sure that you have installed the latest version of iTunes. If there is any fault in iTunes it will impact the success rate of device analysis.
3) If your iTunes backup files have been encrypted, remove the password of the iTunes backup file.
4) Check your USB connection, disconnect and reconnect it, try an alternative USB port.
5) Restart your iPhone and computer.
6) Close any running anti-virus software.