What does BSI-Standard 100-4 cover, and how does it relate to ISO 27031?

100-4 = Notfallmanagement (emergency / business continuity management). It's the BSI's BCM standard, and overlaps heavily with ISO/IEC 27031 (Business Continuity for ICT services).

* The 100-4 Notfallmanagement lifecycle — a BCM loop from initiation through incident handling and exercises back to review. *

The 100-4 process (Notfallmanagement-Lebenszyklus):

Initiierung des Notfallmanagements
  ▼
Konzeption  (Business Impact Analysis, Risikoanalyse, Ist-Zustand, Kontinuitätsstrategien)
  ▼
Umsetzung des Notfallkonzepts
  └→ Kosten-/Aufwandsabschätzung
  └→ Umsetzungsreihenfolge
  └→ Aufgaben & Verantwortung
  └→ Realisierungsbegl. Massnahmen
  ▼
Notfallbewältigung  (Ablauforganisation, Krisenkommunikation, Notfallhandbuch)
  ▼
Tests und Übungen  (Übungsarten, Dokumente, Durchführung)
  ▼
Überprüfung und Verbesserung  (Self-Assessment, Revision, Verbesserungsprozess)
  ▼ (loop)

A key BCM concept: Kapazität over Zeit during an outage — Notbetrieb (limited operations) bridges the time between disruption and full Wiederanlauf (recovery).

Tip: 100-4 was supposed to be replaced by BSI 200-4 in 2022 (modernised). Many organisations still reference 100-4 — both are widely available and conceptually compatible.

Go deeper:

• BSI-Standards overview (official, DE) — 100-4's successor 200-4 gives guidance for a Business Continuity Management System.
• Business continuity planning (Wikipedia) — the BIA/recovery/BCM-lifecycle concepts 100-4 and ISO 27031 both use.