Which statement best describes common incident severity levels and their tolerance in a FOSSE environment?

• A. Sev 1: critical business impact; immediate response; 24/7 on-call; P1
• B. Sev 2: low impact; resolution within days
• C. Sev 3: moderate; resolution within days
• D. Sev 4: cosmetic; no impact; can be ignored

Answer: (A)

In a FOSSE environment, the highest severity level is used for incidents that cause critical business impact and require an immediate, nonstop response. When the front office systems are down in a way that halts trading or essential processing, there’s zero tolerance for downtime, so the situation triggers 24/7 on-call coverage and rapid escalation as a top-priority issue (P1). This reflects the reality that any significant outage can have immediate and severe financial and regulatory consequences, demanding instant action to restore service.

Lower-severity scenarios described as low or moderate impact with days-long resolution imply a much longer tolerance for disruption, which isn’t appropriate for mission-critical front-office operations. The idea of a cosmetic issue that can be ignored likewise doesn’t fit in, since even seemingly minor problems can have cascading effects in complex trading environments.