SDLC blueprint

Handbook

V-Model — major processes & flow maps

```mermaid

V-Model — major processes & flow maps

1. V-Model structure (classic)

flowchart TD REQ["Requirements analysis"] --> SD["System design"] SD --> DD["Detailed design"] DD --> IMPL["Implementation"] IMPL --> UT["Unit testing"] UT --> IT["Integration testing"] IT --> ST["System testing"] ST --> AT["Acceptance testing"] REQ -.->|traces to| AT SD -.->|traces to| ST DD -.->|traces to| IT

Left side descends (decomposition); right side ascends (integration and verification). Dotted arrows show traceability pairing.

2. Traceability flow

flowchart LR R[Requirement ID] --> D[Design element] D --> TC[Test case] TC --> TR[Test result] TR --> EV[Evidence package]

3. Test-level gate decision

flowchart TD TRR["Test readiness review"] --> EX["Execute tests"] EX --> RES{Results} RES -->|All pass| NXT["Proceed to next V-level"] RES -->|Failures| DEF["Defect resolution"] DEF --> EX

4. Change impact (V-Model perspective)

flowchart LR CR["Change request"] --> IA["Impact analysis across V-levels"] IA --> AFF["Affected: req + design + tests"] AFF --> UPD["Update all affected levels"] UPD --> RET["Retest affected V-levels"]

A change to a requirement potentially impacts design, implementation, and tests at multiple V-levels.

5. Phases A–F (V-Model mapping)

Blueprint phase V-Model locus
A Shape Stakeholder needs; concept of operations
B Plan Requirements analysis + acceptance test planning (paired)
C Build System design → detailed design → implementation (left side descent)
D Verify Unit → integration → system testing (right side ascent)
E Release Acceptance testing; deployment readiness
F Learn Operational validation; field feedback; lessons for next cycle

6. Flow details (walkthrough)

V-Model structure — The V is not just a picture; it encodes a discipline. Each left-side level produces specifications that the corresponding right-side level will verify. Test planning happens during design, not after coding. This early pairing catches specification issues before they become implementation defects.

Traceability — The requirement-to-evidence chain is the V-Model's core deliverable. Every requirement must be testable, every test must trace to a requirement, and every test result must be recorded. Gaps in traceability indicate either missing tests or unnecessary requirements.

Test-level gates — Each V-level has an entry check (test readiness) and exit check (test results). Failures feed back to the corresponding development level for resolution, not to a generic "fix bugs" phase.

Change impact — Changes in the V-Model are expensive because they ripple across levels. Impact analysis must consider all affected V-levels: a requirement change may require design updates, code changes, and retesting at unit, integration, system, and acceptance levels.

7. Authoritative sources & further reading

Full curated list: REFERENCE-LINKS.md.

Canonical source

Edit https://github.com/autowww/blueprints/blob/main/sdlc/methodologies/v-model/process-and-flows.md first; regenerate with docs/build-handbook.py.