1. Cyber-weapons exploit a specific vulnerability.
  2. Stealth of the weapon measures the chance that an enemy may find out the use of the weapon and take necessary steps to stop its reuse.
  3. Persistence of the weapon measures the chance that a weapon can still be used in the future, if not used now. Or, put another way, the chance that the enemy finds out their own vulnerability and fixes it, which renders the weapon useless.
  4. Threshold which defines the time when the stakes are high enough to risk the use of a weapon. Beyond the threshold you will gain more than you will lose.