VARIANT OF ANSWER:
Is designed not only to heat mechanic, electrician, automation, but also the technology and organization of production, calculated precision manufacturing of metal structures.
Produce parts of metal structures on the shop floor: it is in the shop - the set performing the quality and accuracy (and geometry, and temporal).
At the construction site to ensure a high level of technology of assembly operations.
Combine A, B, and C, and use the experience of professionals.