The diagrams doctors, engineers, and lawyers actually use.

A multi-loop control block diagram — an inner loop closes G2·G3 around sensor H1, an outer loop closes the whole forward path around sensor H2 routed over the top, and two summing junctions combine the reference with each feedback signal. The kind of cascaded architecture a generic flowchart can't lay out.

Closed-loop PID block diagram with summing junction, controller, and plant — rendered from a signal-flow description without manual layout.

A bowtie with escalation factors on both wings — a preventative and a mitigative barrier are each degraded by a named condition with its own escalation-factor barrier, exercising the full element vocabulary.

The canonical process-safety bowtie — three threats fan in through preventative barrier chains, three consequences fan out through mitigative chains, around the central loss-of-containment top event.

A non-process-industry bowtie — the same threat / barrier / consequence grammar applied to an aviation safety-management scenario, showing the vocabulary travels across domains.

A defence-in-depth bowtie with an escalation factor — a preventative barrier is degraded by a named condition, which is itself controlled by an escalation-factor barrier dropping below the line.

Three-lane BPMN of an on-call rotation handling a production page — L1 triage, L2 investigation, and a Comms lane that posts status updates. Exercises timer intermediate event, severity-based XOR routing, and a self-loop on the triage gate.

Single-pool, two-lane BPMN of a bank loan approval workflow. Clerk completeness check feeds underwriter risk-scoring + review with two end states (approved / rejected). Canonical BPMN test case 7.2.

Two-pool BPMN — external Customer (black-box) and a Pizzeria with Clerk / Chef / Delivery lanes. Exercises message flows across pools, manual / send task markers, and a rework loop on the chef's quality check. Canonical BPMN test case 7.1.

BPMN process for refund handling across Support, Risk, Finance, and an external payment processor, with SLA timer escalation and customer-facing message flows.

The maker hello-world. Arduino Uno + 220Ω resistor + 5mm red LED — D13 → resistor → LED → GND. Tests basic part placement, beside-left MCU, and the iconic Bézier wire arc.

ESP32 DevKit driving a 128×64 OLED display over I²C — four wires (3V3 / GND / SDA / SCL). The standard "first display" project for ESP32 learners.

Four-wire ultrasonic distance sensor wiring — VCC / GND / TRIG / ECHO. The textbook Adafruit / SparkFun tutorial layout used in robotics intro classes.

A system-dynamics model of a viral product whose growth is capped by scaling strain. The engine enumerates every feedback loop and classifies each reinforcing (R) or balancing (B) by Sterman's even/odd rule.

The classic system-dynamics counterintuitive result — widening roads induces demand. The engine enumerates the feedback loops and classifies each reinforcing or balancing by link polarity.

Four-diode full-wave bridge rectifier with a smoothing capacitor and load resistor, written as a compact electrical netlist.

NPN common-emitter amplifier rendered from a five-line SPICE netlist with automatic component placement per IEEE 315.

A practical inverting op-amp stage rendered from a SPICE-style netlist with feedback and input resistors, split supply rails, and a labelled output node.

A netlist-mode circuit that uses the optional dir= orientation hint to draw the pull-up resistor vertically, showing lightweight layout control on top of automatic placement.

A go/no-go market-entry decision as a compact influence diagram — demand observed before entering, a competitor response, and the profit objective — using the inline mode directive form.

The canonical decision-analysis teaching problem as a compact influence diagram — a drill decision informed by a seismic test, the uncertain oil state, and the profit objective, wired as a clean acyclic graph instead of an unrolled tree.

Decision-analysis tree evaluating build-vs-buy vs hybrid for a platform choice — chance nodes with probabilities, automatic expected-value rollback.

Machine-learning decision tree for the classic Iris classifier with split thresholds, sample counts, Gini impurity, and class leaves.

Taxonomy-mode decision tree for front-line support — routes an incoming ticket through outage, billing, and reproducibility gates to the right team.

Ecomap of a refugee family's support network — IRC office, school, clinic, and sponsor family — categorized by resource type per Hartman 1978.

Ecomap charting a client's recovery support network — AA group, family, probation, and therapist — with relationship strength and directional connections.

Quick intake ecomap for a 15-year-old showing family, school, soccer peers, and therapist — drawn in under five minutes during a counseling session.

Estate-planning entity structure with a grantor, irrevocable trust, trustee LLC, holding company, investment LLCs, and beneficiary distributions.

Multi-jurisdiction holding structure with a Delaware corp, UK subsidiary, and Cayman growth fund — the first document in any M&A due diligence package.

Cross-border tax holding structure with Irish IP company, Dutch distribution, and APAC entity — per OECD BEPS transfer-pricing documentation requirements.

Post-Series A cap table showing founders, seed fund, lead VC, angel group, and ESOP pool with ownership percentages — for 409A valuations and board consents.

An ARIS event-driven process chain for purchase requisitions, branching on an XOR connector and re-joining on an AND. The engine validates EPC well-formedness — event/function alternation and the event-cannot-decide rule.

Crow's-foot ERD for an immutable SaaS billing ledger with customers, invoices, payments, refunds, ledger entries, and audit events.

Production-style schema with Customer / Order / OrderLine / Product / Category — typical mid-complexity backend ERD with composite PK on the line-item table.

Crow's-foot ERD for tenants, users, memberships, roles, permissions, invitations, and audit events in a SaaS workspace product.

Classic textbook schema with Student / Course / Enrollment associative entity and labelled relationships — the canonical Elmasri & Navathe ch.3 example.

A loss-of-containment release branched through detection, isolation, and ignition. The engine computes each outcome frequency — safe shutdown, jet fire, dispersion, vapour-cloud explosion — and flags the dominant one.

A large-break loss-of-coolant accident branched through four reactor safety functions. The engine computes every sequence frequency from the initiating rate and per-function failure probabilities, then highlights the dominant accident sequence.

The smallest quantified fault tree — two redundant pumps in an AND gate, so the system fails only if both fail. One minimal cut set, no single point of failure, with a computed top-event probability.

A shared basic event feeds two gates — the case naive fault-tree tools get wrong. MOCUS applies absorption so the supersets collapse, leaving two single points of failure that a shape stencil would miss.

Voting, inhibit, house and undeveloped events in one tree — a 2-of-2 relief group, an over-pressure inhibited by a heater condition, and an order-3 minimal cut set with the tighter MCUB probability.

The canonical introductory fault tree — an OR top over an AND sub-fault and an OR no-voltage branch, with a probability on every basic event. A faithful, quantified reproduction of the standard worked example.

Three-network FBD pipeline that debounces a bottle sensor with a 50ms TON, takes the rising edge with R_TRIG, counts up to 24 bottles per case with CTU, and self-resets when the case is full. A real production-line pattern that exercises timer + edge-detector + counter + named-instance references in sequence.

Two-network FBD of the canonical PLC seal-in circuit — start-button rising edge sets a latch, stop and emergency-stop break it. Exercises declared variables, multi-network programs, inline expression notation, and negation bubbles.

Two-network FBD that clamps an operator-entered tank-level setpoint to the safe range [0, 95]% via LIMIT, and raises an alarm if the operator types an out-of-range value. Uses LT and GT comparison blocks, the LIMIT selection block, and demonstrates REAL (orange) and BOOL (black) wires carrying different data types in one diagram.

Ishikawa 6M root-cause analysis for a solder joint defect spike on an electronics assembly line.

Ishikawa fishbone for a website traffic drop — six causal categories covering content, technical SEO, backlinks, UX, competition, and algorithm changes.

Flowchart of a trunk-based CI/CD pipeline — build, test, security scan, staging gate, and production deploy with automatic rollback on failed smoke tests.

ISO-style flowchart for a claims team triaging coverage, fraud risk, document completeness, manual review, and payment or denial outcomes.

Flowchart mapping the full order-to-delivery path with inventory and payment decision gates, exception handling, and a single End terminal.

A design FMEA for an electric-vehicle battery pack. The engine flattens the failure chain, computes RPN = S × O × D, and derives the AIAG-VDA Action Priority — keeping a S10 safety failure High even when its RPN looks low.

A process FMEA for an injection-moulding line, ranked the legacy way by RPN. The engine computes RPN = S × O × D for every (step, mode, cause) row and flags the ones that breach the 100 threshold.

Three-generation BRCA1 family genogram with hereditary breast/ovarian cancer conditions — captured at intake before formal clinical pedigree analysis.

Foster-care genogram for a real LATAM child-protection case — biological parents (cohabitation ended), abuse, current foster placement (dotted secondary link), unknown-count siblings, and a maternal uncle as known-relative-with-unknown-ancestry.

Three-generation family medical history genogram with multi-condition color annotations using fill zones — heart disease, diabetes, cancer, hypertension.

Minimal nuclear family genogram — married couple, one child, marriage date — the clinical intake starting template per McGoldrick 2020 notation.

Three-generation Potter family genogram with emotional relationship lines — cutoff, hostile, and close — illustrating McGoldrick relational notation.