In 1973 "Several Provisions on Environmental Protection and Improvement (Trial Draft)", China put forward the principle that all pollution prevention projects in newly built, expanded and rebuilt enterprises must be designed, constructed and put into operation at the same time as the main project.
Extended data:
Article 24 of China's "Safety Production Law" stipulates that the safety facilities of new construction, reconstruction and expansion projects (hereinafter referred to as construction projects) of production and business units must be designed, constructed and put into production and use at the same time as the main project. Investment in safety facilities should be included in the budget estimate of construction projects.
In order to maintain or expand the scale of production and operation, production and business units often need to carry out related engineering construction. If the safety facilities of construction projects are not designed, constructed and put into production and use at the same time, unsafe factors and hidden dangers will be left behind, which may lead to production safety accidents in the process of production and operation. The principle of simultaneous design, simultaneous construction, simultaneous production and use is called the "three simultaneities" principle.
References:
Baidu Encyclopedia-"Three simultaneities" Principle