How to speed up the decision making process in big company ?

The problems are the following :

• This company needs to respect the hierarchy to move forward with projects which is sometimes waste of time but necessary.
• it is very large corporation, the process tends to be very long it because it will affect all departments of the company and it takes so long to take decisions in order to avoid corruption
• A good solution could to find a balance between efficiency, security, and anti-corruption efforts.

Please suggest a few solutions in paragraph forms