What do you see as the biggest challenge for maintaining these systems and their accuracy?

Fundamentals of A/C Avionics

Address the following in your primary, original posting:

Based on your research, describe the differences and similarities between an Autopilot and AFCS. Also, discuss the basis for an autopilot system in modern commercial aircraft and the various components of an autopilot system, particularly focusing on how they interact with each other. Finally, discuss your thoughts on the benefits of these systems as it relates to pilot fatigue and overall operational safety. What do you see as the biggest challenge for maintaining these systems and their accuracy?