The implementation of large projects requires significant analysis and preliminary calculations. In order to build a manufacturing enterprise, it is necessary to minimize the possibility of creating unprofitable production first of all. Administrative, residential (including multi-storey) and other buildings also need to clarify all technical and economic indicators so that the organization that will subsequently maintain and operate such an object can pay for it and does not face inflated maintenance costs.

To solve such issues, a set of preliminary design works (FEED) is carried out in advance with the preparation of appropriate documentation. Without certain experience in this matter, you can face a number of problems, since there are several types of pre-design documentation, which is related to the calculation of technical and economic indicators:

FS, TEC, etc.

Detailed design documentation is the final complete version, on the basis of which construction and installation work can begin. The development of the draft detailed design documentation usually begins almost immediately after the design (feasibility study stage), i.e. it occurs almost in parallel. In order not to waste time,  DDD stage is started as soon as a positive conclusion is received on the approved part of the feasibility study.