It becomes a challenge to fit or repair any part outside a tall building. The risks involved in such cases are very high. Some of the environments may be totally inaccessible hence making it hard to accomplish the desired task.
Use of cherry picker especially on buildings makes it possible to carry out some task effectively such as window maintenance. Places which may be hard to access can either be below or above the ground level. Cherry pickers may also be referring to as boom lift since they are operated by powered mechanisms.