With what year during the perestroika period in the USSR is the transition to the reform of the political system associated?

Since 1987, the Plenum of the CPSU Central Committee has decided to make the political process democratic. The elections of party secretaries and leaders began to be introduced, which made it possible to increase the role of workers in the management of production. In 1988, at the 19th All-Russian Conference, it was decided to build a civil society in the country, to make the state legal. A two-tier system of representative power was established, changes were made to the electoral legislation, the Supreme Soviet of the USSR became a permanent parliament in the country.