What is the relationship between the association of subordinates in decisions making and the effectiveness of these last ?

Thanks for invitation. When the decision is made by group/team, it is easy to implement, maintain and sustain. 

thanks

i agree with all answers

The decision made in teams with mutual understanding proves best ones and you feel ease in implementation. 

It is more effective and practical if we involve all stack holder in the decision making process. Through this process not only we could be able to get the best solution as well as we take the ownership from all corners.

I agree with Md. Fazlur Rahman................

Thanks  for invitation,

Agree with Mr. Omar saad , as this exactly  the main principle of  what is called "Management by Objectives and Results"

Thanks 

A strong relationship can be. Found here, this called manage by participation