The purpose of the appointment of a technical advisor is to support the interested party in matters and practices related to the science of engineering and which he cannot cope with without his assistance, due to the lack of knowledge, experience and scientific training.

The engineer is called upon to check or evaluate the object of the assignment and to present the results in a reasoned and comprehensible manner to the interested party in order for him to be able to make a decision or proceed with a process (purchase, construction, etc.). In cases where the assistance of an engineer is required by law, then the necessary documents and plans (technical report, autopsy report, impression, tables, topographical diagram, etc.) are drawn up to accompany his conclusion.

The most common cases where the presence of a technical consultant is requested on behalf of the interested party, or the assistance of an engineer is required, are in disputes or disagreements of the interested party or between the interested parties on technical issues such as the boundaries of the subdivision of a plot of land, the identification of the boundaries of a property , technical issues between co-owners, etc.