Why do organizations need an OD ( Organizational Development ) consultant?

There are compelling reasons because of which organizations need an OD Consultant:

1.Day to day involvement in running an organization is does not allow one to develop a bird's eye view of the entire domain in which the organization exists.

2.An OD Consultant is supposed to closely look for flaws in the culture of an organization which need to be fixed through different types of intervention.

3.The silo effect is inevitable and therefore someone who is dedicated solely to look around for ways and means to develop an organization is best equipped to overcome the retarding impacts of silos.  

4.People make organizations and their contribution in taking the organization to the next level is absolutely essential.Therefore, interventions need to be designed and implemented to utilize the people's potential to develop the organization.