When Just A Garage Door Panel Gets Damaged: You are able to replace just one of them instead of the whole door.
When A Panel Is Aged Or Unattractive To The Eye: You may want to replace just a panel or two.
More Cost Effective: If your garage door is more like a shed, replacing a panel might be more cost effective.
Minimal Inconvenience During Simple Panel Repair/Install: An experienced installer can oftentimes install these panels within hours, and you can even use the garage in the meantime.
Whether To Replace Entire Door Versus Panel(s): One thing to take into consideration, is the possibility of the panels not matching the existing door due to age of the existing panels as well as weather aging and other damage.