Operators typically rely on two or three main suppliers, and the lead contractor on one project may integrate equipment from others.
The procedures for screening contractors on projects financed by the city's Economic Development Corporation, as the stadium was, are less rigorous than for projects built and paid for by the city.
The problems also underscore the inadequacies in the process by which the city vets contractors on projects like the stadium, which was financed in significant part by the city but built by a private developer, Tishman-Speyer.
The decades-old "Hollywood Model" enables entertainment professionals to work as contractors on projects spanning many different companies, because their labor unions provide continuity in health care and pension benefits.
Balachandran has worked closely with other conservators, museum professionals and contractors on projects regarding object-conservation assessments, surveys and treatments.
However, BIM use by mid-sized contractor firms (that is, firms with 50 500 employees that can successfully compete with larger contractors on projects costing a maximum of 50 million Euros) is relatively unknown.
Knaian runs a small electrical engineering company called NK Labs, one of the main contractors working on "Project Ara" (which is named after him).
The contractors on the project are Consolidated Contractors, based in Athens, and the Turkish company TAV.
In a loud, straining voice, Mr. Aidala blamed the collapse on a series of missteps by the city, the contractors on the project and the crane operator.
