What were 3 main reasons for perestroika and glasnost to be introduced?

3 Reaons:

Inefficient economy

Ineffective government

External reasons

With Perestroika,the economy of Soviet Union will improve as it's aim was to recontruct the industries of USSA.

Glasnost allow the freedom of speech.By allowing this reform,the people will be able to communicate with the government to built a better USSR.The government will also be able to hear the ''voices of the people'' and seek to improve.

Perestroika was also to reduce military spending since USSA was geared towards arms during the WW2 and this policy seek to reduce this spending.