Emergency Evacuation aboard Vessels and platforms

in the event of an emergency, the need to ensure that all personnel are evacuated can not be overemphasized as a value can not be placed on a single human life, as such safety procedures requires that evacuation must be in place, the Chevron rig explosion aboard KS ENdeavor is a typical example  out of 154 personnel aboard the vessel 152 were safely evacuated [1]. can this be termed as successful?, could the loss of lives have been prevented? when is the ideal moment to abadon a rig in the event of an incident occuring?

typical means for evacuating personnel aboard vessels and platforms are

(a) Conventional life boats

 (b) Free fall Life Boats

which of these is preferred and based on the comparative advantages? 

References:

http://www.drillingahead.com/page/chevron-ks-endeavor-platform-on-fire-o...