- Short answer
-
There is no general rule - as the minimal amount depends on the system, its stakeholders, criticality, complexity, size and/or risks.
- Longer answer
-
We suggest to always explain, document or specify the following aspects:
- 3-5 central quality requirements, expressed in scenarios.
- Context view and external interfaces
- Brief explanation of your solution strategy, the most important decisions influencing the implementation or operation of the system.
- Building block view, level 1.
- Most important crosscutting concepts.
Prefer to learn arc42 hands-on?
Practical architecture training, most classes taught by Peter Hruschka and Gernot Starke — the people who created arc42 and maintain this FAQ (dates with other trainers say so) — and solid preparation for iSAQB certifications.
Next dates
- 15–17 Sep 2026 DE Req4Arc · Frankfurt/Maingetting your requirements right
- 29 Sep–1 Oct 2026 EN Mastering SW Architectures · onlineperfect preparation for iSAQB CPSA-Foundation certification · with Wolfgang Reimesch
- 27–28 Oct 2026 DE ADOC · Züricharchitecture documentation · with Gernot Starke
- 24–26 Nov 2026 DE IMPROVE · Hamburgevolve and maintain systems · with Carola Lilienthal & Gernot Starke
- 1–4 Dec 2026 DE Mastering SW Architectures · Münchenperfect preparation for iSAQB CPSA-Foundation certification
- 2–5 Mar 2027 DE Mastering SW Architectures · Münchenperfect preparation for iSAQB CPSA-Foundation certification
- 9–11 Mar 2027 DE Req4Arc · Münchengetting your requirements right
- 2–3 Jun 2027 DE ADOC · Mannheim oder Frankfurt (t.b.d.)architecture documentation
All courses and dates: trainings.arc42.org · as of 4 Aug 2026