One of the key requirements for a patent for a technical process innovation to be successfully defended is that there must be something genuinely innovative about the subject matter of the patent. There has to be 'novelty' and an inventive step.
On occasions, patent applications are granted where there is no such step. Where the subject of a patent is an obvious application of existing knowledge, the patent is subject to challenge.
In a recent case, an attempt to enforce patent rights for a method of preparation of blood plasma failed and brought about the revocation of the patent because it lacked novelty and an inventive step.