Designate assembly areas both inside and outside the workplace. Assembly locations within the building are often referred to as "areas of refuge." Make sure that each assembly area has sufficient space to accommodate all workers reporting to it. Exterior assembly areas, used when the building must be partially or completely evacuated, are typically located in parking lots or other open areas away from busy streets. Try to designate assembly areas up-wind of the building from the most common (i.e., prevailing) wind direction. When designating an assembly area, consider (and try to minimize) the possibility of workers interfering with emergency response operations. The most effective method to evaluate potential area(s) of refuge is to conduct a pre-evacuation drill.

OSHA

Thanks a lot of dear bimr

Hi ,
Good to define several assembly points and refer to the wind direction to gather the people at the right place . This means you need to install wind socks in your facility .
Note : evacuation plan should be prepared and communicated to the people together with drills to evaluate the efficiency.
My view
Pierre

Thanks to all the friends who participated in the discussion.
Dear friends, in your industry, while investigating the accident, did you come across a case where the Emergency Assembly point has a role in adverse consequences? That is, the place you designated is vulnerable and affected by the accident.
Please let your friends know if they have any experience with this.