The quality of being able to be used or fixed easily.
Serviceability is a good thing because it means something can be used for a long time and can be fixed if it breaks.
Examples:
The serviceability of this tool is very good.
We need to check the serviceability of the car before we buy it.
The serviceability of the machine is important for the factory.
The serviceability of this toy is so bad, it broke the first time I used it!
The serviceability of this phone is so good, it will never break!
The serviceability of this bridge is so good, it will never fall down.