The objective of this research is to analyze risks which affect the key process in crisis protection: a case study of partial blackout. The research was carried out by applying business continuity management (BCM) to electrical energy transmission. It is found that there are 7 key processes needed: 1) Electricity Generating Planning by Electricity Generating Plant, 2) Electricity Machine Running, 3) Fuel Using Management, 4) Fuel Supplying, 5) Electricity Distribution Planning, 6) Electricity Generating and Quality Control as required by the National Control Center, and 7) Electricity Operation Control and Distribution through delivery points. In addition, the priority of restoring processes are 6), 7), 2), 1), 3), 4) and 5), respectively. There are 6 risks which cause partial blackout and shall be manipulated in priority order as follows: 1) fuel used for generating electricity does not comply with the generating plan of the Electricity Generating Authority of Thailand; 2) the electricity plant is damaged by accident; 3) disaster is caused by the electricity transmission system sabotage; 4) the security of electricity system is under the standard; 5) the electricity transmission system is damaged by accident;
6) disaster caused by electricity plant sabotage.