- Short answer
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There is no general rule - as the minimal amount depends on the system, its stakeholders, criticality, complexity, size and/or risks.
- Longer answer
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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
- 24–26 Nov 2026 DE IMPROVE · Hamburg waitlistevolve and maintain systems · with Carola Lilienthal & Gernot Starke
- 1–4 Dec 2026 DE MSA · München waitlistperfect preparation for iSAQB CPSA-Foundation certification
- 23–25 Feb 2027 EN MSA · onlineperfect preparation for iSAQB CPSA-Foundation certification · with Wolfgang Reimesch
- 2–5 Mar 2027 DE MSA · Münchenperfect preparation for iSAQB CPSA-Foundation certification
- 9–11 Mar 2027 DE Req4Arc · Münchengetting your requirements right
- 13–15 Apr 2027 EN IMPROVE · onlineevolve and maintain systems · with Wolfgang Reimesch
- 2–3 Jun 2027 DE ADOC · Mannheimarchitecture documentation · with Dr. Gernot Starke
- 8–11 Jun 2027 DE MSA · Mannheimperfect preparation for iSAQB CPSA-Foundation certification
All courses and dates: trainings.arc42.org · as of 20 Oct 2026