The opinion on the presence or absence of patent infringement may be required both for companies that have received claims about their illegal use of other persons’ patented inventions, and right holders valuing their intellectual property to plan actions against the infringer. The presence of such opinion can be helpful for the protection against unjustified claims and for the establishment of the fact of violation of their rights in a timely manner and preparation for their protection in advance.

In a number of cases related to alleged patent infringement, the only available research object is a product available on the market that should be legally purchased and investigated, for example, with full disassembly of the product and study of all its components or by performing a physicochemical analysis of the substance. To ensure the quality of such study, the presence of the relevant specialist’s technical or scientific education, experience and special knowledge plays an important role, making it possible to understand correctly the structure of such object, and in the case when the technical solutions in the studied object belong to several fields of art, - the knowledge and experience of several persons skilled in the pertinent art are required. Each specialist preparing an opinion should have experience in applying the theory of equivalents so that his/her opinion on the presence or absence of patent infringement is fully justified.

Any opinion should be prepared with due consideration for its possible use in disputes on the protection of rights, which means its careful re-examination by patent attorneys and specialists of the other, opposing party, the purpose of which will be to refute any conclusions arising from the opinion that are undesirable for them. Thus, the preparation of a high-quality and reliable opinion on patent infringement requires an extremely high qualification of a person skilled in the art regarding a patented solution, experience in preparing opinions in this area, as well as the use of an objective and logically harmonious methodology for preparing an opinion.