Thinking in Diagrams

A textbook about diagrammatic thinking, with a diagram lab in it, covering the systems and feedback family of diagrams.

Thinking in Diagrams

Chapter 1

What Is a Diagram For?

Causal-loop diagram Variables: parking charges; online shopping; visitors to the high street; takings per shop; empty shops. Effects: parking charges to visitors to the high street (polarity not yet set, hypothesis); online shopping to visitors to the high street (polarity not yet set, hypothesis); visitors to the high street to takings per shop (polarity not yet set); takings per shop to empty shops (polarity not yet set, hypothesis); empty shops to visitors to the high street (polarity not yet set, hypothesis). parking charges online shopping visitors to the high street takings per shop empty shops Evidencemore supportedless supported

Thinking in Diagrams

Chapter 2

Drawing the Boundary

System context map: the household Boundary the household contains no external entities. External entities outside every boundary: Priya's employer; the landlord; the supermarket; the energy supplier; Dev. Exchanges: wages, from Priya's employer to the household (owner: the household); rent, from the household to the landlord (owner: the household); repairs, from the landlord to the household (owner: the household); groceries, from the supermarket to the household (owner: the household); grocery payments, from the household to the supermarket (owner: the household); electricity, from the energy supplier to the household (owner: the household); bill payments, from the household to the energy supplier (owner: the household); a furnished room, from the household to Dev (owner: the household); room rent, from Dev to the household (owner: the household). the household wages rent repairs groceries grocery payments electricity bill payments a furnished room room rent Priya's employer the landlord the supermarket the energy supplier Dev

Thinking in Diagrams

Chapter 3

Surfacing Influences

Influence map: time Nia spends reading Central outcome: time Nia spends reading. Other variables: reading level; length of the books she picks; enjoyment of reading; evenings a parent reads with her; books at home; library visits per month; screen time; hours of after-school clubs. Claims: time Nia spends reading to reading level (influence claim); reading level to length of the books she picks (influence claim); length of the books she picks to time Nia spends reading (influence claim); enjoyment of reading to time Nia spends reading (influence claim); books at home to time Nia spends reading (influence claim); screen time to time Nia spends reading (influence claim); hours of after-school clubs to time Nia spends reading (influence claim); library visits per month to books at home (influence claim); evenings a parent reads with her to enjoyment of reading (influence claim). time Nia spends reading reading level length of the books she picks enjoyment of reading evenings a parent reads with her books at home library visits per month screen time hours of after-school clubs

Thinking in Diagrams

Chapter 4

Loops That Amplify, Loops That Correct

Causal-loop diagram: R1 spiral Variables: sleep debt; afternoon caffeine; hours slept. Effects: sleep debt to afternoon caffeine (+, same direction); afternoon caffeine to hours slept (−, opposite direction); hours slept to sleep debt (−, opposite direction). Loop R1 spiral, reinforcing: sleep debt, afternoon caffeine, hours slept, and back to sleep debt. + − − sleep debt afternoon caffeine hours slept R1spiral

Thinking in Diagrams

Chapter 5

Delays, External Drivers, and Competing Loops

Causal-loop diagram: B1 relief by widening; B2 induced traffic; B3 building on the outskirts Variables: lanes on the main road; travel time; car trips; homes on the outskirts; regional population (external driver). Effects: travel time to lanes on the main road (+, same direction); lanes on the main road to travel time (−, opposite direction, viewpoint: Commuters); travel time to car trips (−, opposite direction); car trips to travel time (+, same direction, nonlinear); travel time to homes on the outskirts (−, opposite direction, with a delay, hypothesis, viewpoint: Council); homes on the outskirts to car trips (+, same direction, viewpoint: Residents); regional population to car trips (+, same direction). Loop B1 relief by widening, balancing: travel time, lanes on the main road, and back to travel time. Loop B2 induced traffic, balancing: travel time, car trips, and back to travel time. Loop B3 building on the outskirts, balancing: travel time, homes on the outskirts, car trips, and back to travel time. Boundary the town's road network contains: lanes on the main road; travel time; car trips; homes on the outskirts. Outside every boundary: regional population. Behavior note: Travel time falls, then returns: B1 leads in the first year, B2 and B3 over the next few.. the town's road network + −Commuters − + −Council +Residents + lanes on the main road travel time car trips homes on the outskirts ‹regional population› B1relief by widening B2induced traffic B3building on the outskirts Travel time falls, thenreturns: B1 leads in thefirst year, B2 and B3 overthe next few. Evidencemore supportedless supportedViewpointsCommutersCouncilResidents

Thinking in Diagrams

Chapter 6

What Accumulates

Stock & flow diagram: water in tub Stocks: water in tub (liters). Auxiliaries: tap setting; drain opening. Flows: filling, from a cloud to water in tub (liters per minute); draining, from water in tub to a cloud (liters per minute). Stock equation: change in water in tub = filling − draining. Signals: tap setting to filling, +; drain opening to draining, +; water in tub to draining, +. filling draining + + + literswater in tub tap setting drain opening change in water in tub = filling − draining

Thinking in Diagrams

Chapter 7

Stocks Inside Feedback

Stock & flow diagram: people susceptible; people ill; people recovered Stocks: people susceptible (people); people ill (people); people recovered (people). Auxiliaries: infectious contacts; reported cases; caution. Flows: falling ill, from people susceptible to people ill (people per day); recovering, from people ill to people recovered (people per day). Signals: people susceptible to infectious contacts, +; people ill to infectious contacts, +; infectious contacts to falling ill, +; people ill to recovering, +; people ill to reported cases, +, with a delay; reported cases to caution, +; caution to infectious contacts, −. Loop R1 contagion, reinforcing: people ill, infectious contacts, falling ill, which fills people ill. Loop B1 depletion, balancing: people susceptible, infectious contacts, falling ill, which drains people susceptible. Loop B2 caution, balancing: people ill, reported cases, caution, infectious contacts, falling ill, which fills people ill. falling ill recovering + + + + + + − peoplepeople susceptible peoplepeople ill peoplepeople recovered infectious contacts reported cases caution R1contagion B1depletion B2caution

Thinking in Diagrams

Chapter 8

Sense, Compare, Correct

Feedback control diagram: room temperature Variables: desired temperature (target); temperature gap (gap); boiler output (corrective action); room temperature (controlled variable); thermometer reading (measured value); outdoor temperature (external driver). Signals: desired temperature to temperature gap, +; thermometer reading to temperature gap, −; temperature gap to boiler output, +; boiler output to room temperature, +; room temperature to thermometer reading, +; outdoor temperature to room temperature, +. Loop B1 heating, balancing: temperature gap, boiler output, room temperature, thermometer reading, and back to temperature gap. Control loop B1: temperature gap → boiler output → room temperature → thermometer reading; target: desired temperature. + − + + + + desired temperaturetarget temperature gapgap boiler outputcorrective action room temperaturecontrolled variable thermometer readingmeasured value ‹outdoor temperature› B1heating

Thinking in Diagrams

Chapter 9

Anticipation, Limits, and Nested Control

Feedback control diagram: her pace; her finish time Variables: target finish time (target); minutes behind plan (gap); target pace (corrective action); seconds too slow (gap); her effort (corrective action, at most the effort she can hold to the finish); her pace (controlled variable); lap pace (measured value); her finish time (controlled variable); projected finish time (measured value); hill's gradient (external driver); effort she picks by feel (override). Signals: target finish time to minutes behind plan, −; projected finish time to minutes behind plan, +; minutes behind plan to target pace, −; target pace to seconds too slow, −; lap pace to seconds too slow, +; seconds too slow to her effort, +, deadband ±5 seconds per kilometer; her effort to her pace, −; her pace to lap pace, +, with a delay; her pace to her finish time, +; her finish time to projected finish time, +; hill's gradient to her pace, +; hill's gradient to her effort, +; effort she picks by feel to her effort, +. Loop B1 holding the pace, balancing: seconds too slow, her effort, her pace, lap pace, and back to seconds too slow. Loop B2 keeping to the finish time, balancing: minutes behind plan, target pace, seconds too slow, her effort, her pace, her finish time, projected finish time, and back to minutes behind plan. Control loop B1: seconds too slow → her effort → her pace → lap pace; target: target pace. Control loop B2: minutes behind plan → target pace → her finish time → projected finish time; target: target finish time. Nested: B1 inside B2: target pace sets seconds too slow. Feedforward: hill's gradient → her effort. − + − − + +deadband ±5 seconds per kilometer − + + + + + + target finish timetarget minutes behind plangap target pacecorrective action seconds too slowgap her effortcorrective actionat most the effort she can hold to the finish her pacecontrolled variable lap pacemeasured value her finish timecontrolled variable projected finish timemeasured value ‹hill's gradient› effort she picks by feeloverride B1holding the pace B2keeping to the finish time

Thinking in Diagrams

Chapter 10

Structures That Recur

System archetype: fixes that fail Variables: pests; spraying (symptomatic solution); natural predators (side effect). Effects: pests to spraying (+, same direction); spraying to pests (−, opposite direction); spraying to natural predators (−, opposite direction); natural predators to pests (−, opposite direction, with a delay). Loop B1 fewer pests, balancing: pests, spraying, and back to pests. Loop R1 pests return, reinforcing: pests, spraying, natural predators, and back to pests. Declared: fixes that fail, which the structure matches, with its delay. + − − − pests sprayingsymptomatic solution natural predatorsside effect B1fewer pests R1pests return Archetype: fixes that fail

Thinking in Diagrams

Chapter 11

Diagnosing Tangled Situations

System archetype: escalation; eroding goals Variables: our party's size; other families' parties; how ours compares; our limit on guests; guests over our limit. Effects: our party's size to how ours compares (+, same direction); how ours compares to our party's size (−, opposite direction); other families' parties to how ours compares (−, opposite direction); how ours compares to other families' parties (+, same direction); our limit on guests to guests over our limit (−, opposite direction); guests over our limit to our party's size (−, opposite direction, with a delay); our party's size to guests over our limit (+, same direction); guests over our limit to our limit on guests (+, same direction). Loop B1 ours grows, balancing: our party's size, how ours compares, and back to our party's size. Loop B2 theirs grow, balancing: other families' parties, how ours compares, and back to other families' parties. Loop B3 cut back, balancing: our party's size, guests over our limit, and back to our party's size. Loop B4 limit up, balancing: guests over our limit, our limit on guests, and back to guests over our limit. Declared: escalation, which the structure matches. Declared: eroding goals, which the structure matches, with its delay. + − − + − − + + our party's size other families' parties how ours compares our limit on guests guests over our limit B1ours grows B2theirs grow B3cut back B4limit up Archetype: escalation Archetype: eroding goals

Thinking in Diagrams

Chapter 12

Choosing the Diagram

System context map: Ana's hives Boundary Ana's hives contains no external entities. External entities outside every boundary: the farm next door; honey buyers; the bee inspector. Exchanges: pollination, from Ana's hives to the farm next door (owner: Ana's hives); notice of spraying, from the farm next door to Ana's hives (owner: Ana's hives); jars of honey, from Ana's hives to honey buyers (owner: Ana's hives); payment, from honey buyers to Ana's hives (owner: Ana's hives); inspection, from the bee inspector to Ana's hives (owner: Ana's hives); hive records, from Ana's hives to the bee inspector (owner: Ana's hives). Ana's hives pollination notice of spraying jars of honey payment inspection hive records the farm next door honey buyers the bee inspector

Thinking in Diagrams

Field guide

How the eighteen types relate The eighteen types’ names in boxes, grouped by family, and fifteen lines between them, none with an arrowhead. Each line is a relationship from the table, not an effect, and carries no arrowhead. Systems & feedback: system context map, influence map, causal loop diagram, stock & flow diagram, feedback control diagram, system archetype. Processes & experience: process map, swimlane diagram, BPMN, value stream map, service blueprint, customer journey map. Strategy & decisions: theory of change, decision tree, stakeholder map, capability map, risk bow-tie, Wardley map. The lines: influence map and causal loop diagram, converted to; causal loop diagram and stock & flow diagram, redrawn by hand; causal loop diagram and feedback control diagram, a role written above each variable; stock & flow diagram and feedback control diagram, stock, flows and signals; causal loop diagram and system archetype, a declared archetype; system context map and stakeholder map, parties on both; process map and swimlane diagram, a lane for each party; process map and BPMN, run by software; swimlane diagram and BPMN, swimlanes; process map and value stream map, with data added; customer journey map and service blueprint, the work behind each one; process map and service blueprint, flowchart; service blueprint and BPMN, more internally focused; process map and Wardley map, how they could change; customer journey map and Wardley map, give the needs. Each line is a relationship from the table,not an effect, and carries no arrowhead. Systems & feedback Strategy & decisions Processes & experience systemcontext map influence map causal loopdiagram stock & flowdiagram feedbackcontroldiagram systemarchetype process map swimlanediagram BPMN value streammap serviceblueprint customerjourney map theory ofchange decisiontree stakeholdermap capabilitymap riskbow-tie Wardley map converted to redrawnby hand a role writtenabove eachvariable stock, flowsand signals a declaredarchetype partieson both a lane foreach party run bysoftware swimlanes with dataadded the workbehindeach one flowchart more internallyfocused how theycouldchange give theneeds

Thinking in Diagrams

Field guide

System context map

System context map: the household Boundary the household contains no external entities. External entities outside every boundary: Priya's employer; the landlord; the supermarket; the energy supplier; Dev. Exchanges: wages, from Priya's employer to the household (owner: the household); rent, from the household to the landlord (owner: the household); repairs, from the landlord to the household (owner: the household); groceries, from the supermarket to the household (owner: the household); grocery payments, from the household to the supermarket (owner: the household); electricity, from the energy supplier to the household (owner: the household); bill payments, from the household to the energy supplier (owner: the household); a furnished room, from the household to Dev (owner: the household); room rent, from Dev to the household (owner: the household). the household wages rent repairs groceries grocery payments electricity bill payments a furnished room room rent Priya's employer the landlord the supermarket the energy supplier Dev

Thinking in Diagrams

Field guide

Influence map

Influence map: time Nia spends reading Central outcome: time Nia spends reading. Other variables: reading level; length of the books she picks; enjoyment of reading; evenings a parent reads with her; books at home; library visits per month; screen time; hours of after-school clubs. Claims: time Nia spends reading to reading level (influence claim); reading level to length of the books she picks (influence claim); length of the books she picks to time Nia spends reading (influence claim); enjoyment of reading to time Nia spends reading (influence claim); books at home to time Nia spends reading (influence claim); screen time to time Nia spends reading (influence claim); hours of after-school clubs to time Nia spends reading (influence claim); library visits per month to books at home (influence claim); evenings a parent reads with her to enjoyment of reading (influence claim). time Nia spends reading reading level length of the books she picks enjoyment of reading evenings a parent reads with her books at home library visits per month screen time hours of after-school clubs

Thinking in Diagrams

Field guide

Causal loop diagram

Causal-loop diagram: R1 spiral Variables: sleep debt; afternoon caffeine; hours slept. Effects: sleep debt to afternoon caffeine (+, same direction); afternoon caffeine to hours slept (−, opposite direction); hours slept to sleep debt (−, opposite direction). Loop R1 spiral, reinforcing: sleep debt, afternoon caffeine, hours slept, and back to sleep debt. + − − sleep debt afternoon caffeine hours slept R1spiral

Thinking in Diagrams

Field guide

Stock & flow diagram

Stock & flow diagram: water in tub Stocks: water in tub (liters). Auxiliaries: tap setting; drain opening. Flows: filling, from a cloud to water in tub (liters per minute); draining, from water in tub to a cloud (liters per minute). Stock equation: change in water in tub = filling − draining. Signals: tap setting to filling, +; drain opening to draining, +; water in tub to draining, +. filling draining + + + literswater in tub tap setting drain opening change in water in tub = filling − draining

Thinking in Diagrams

Field guide

Feedback control diagram

Feedback control diagram: room temperature Variables: desired temperature (target); temperature gap (gap); boiler output (corrective action); room temperature (controlled variable); thermometer reading (measured value); outdoor temperature (external driver). Signals: desired temperature to temperature gap, +; thermometer reading to temperature gap, −; temperature gap to boiler output, +; boiler output to room temperature, +; room temperature to thermometer reading, +; outdoor temperature to room temperature, +. Loop B1 heating, balancing: temperature gap, boiler output, room temperature, thermometer reading, and back to temperature gap. Control loop B1: temperature gap → boiler output → room temperature → thermometer reading; target: desired temperature. + − + + + + desired temperaturetarget temperature gapgap boiler outputcorrective action room temperaturecontrolled variable thermometer readingmeasured value ‹outdoor temperature› B1heating

Thinking in Diagrams

Field guide

System archetype

System archetype: fixes that fail Variables: pests; spraying (symptomatic solution); natural predators (side effect). Effects: pests to spraying (+, same direction); spraying to pests (−, opposite direction); spraying to natural predators (−, opposite direction); natural predators to pests (−, opposite direction, with a delay). Loop B1 fewer pests, balancing: pests, spraying, and back to pests. Loop R1 pests return, reinforcing: pests, spraying, natural predators, and back to pests. Declared: fixes that fail, which the structure matches, with its delay. + − − − pests sprayingsymptomatic solution natural predatorsside effect B1fewer pests R1pests return Archetype: fixes that fail

Thinking in Diagrams

Field guide

Process map

Renewing a UK passport by post, as a process map Ten shapes from top to bottom, each joined to the next by a line with an arrowhead, and two to their right. An oval: passport expired, or too little time left. A diamond: lost, stolen or damaged? Its line marked yes runs right to an oval, replace it instead; its line marked no runs down. A box: get a paper form. A box: get 2 new, identical printed photos. A box: fill in the form and pay £115.50. A box: post the form, photos and old passport. A box: HM Passport Office checks the application. A diamond: more information or an interview? Its line marked yes runs right to a box, send more information, or attend an interview, whose line runs up and back into the box where HM Passport Office checks the application; its line marked no runs down. A box: new passport sent by courier or Royal Mail. An oval: new passport, with a new number. passport expired, ortoo little time left lost, stolenor damaged? yes replace itinstead no get a paper form get 2 new, identicalprinted photos fill in the formand pay £115.50 post the form, photosand old passport HM Passport Officechecks the application more informationor an interview? yes send more information,or attend an interview no new passport sent bycourier or Royal Mail new passport, witha new number

Thinking in Diagrams

Field guide

Swimlane diagram

Consent forms for a school trip, as a swimlane diagram Three lanes, one above another, each named at its left: teacher, school office, parent. Time runs left to right, and each step sits in the lane of whoever does it, joined to the next by a line with an arrowhead. In the teacher's lane, an oval: trip planned; its line runs right to a box: write the letter and form, whose line runs down into the school office's lane to a box: copy and send forms home, whose line runs down into the parent's lane to a box: read the letter. Its line runs right to a box: return the signed form, whose line runs right and up into the school office's lane to a diamond: all forms back by the deadline? Its line marked no runs left to a box: send a reminder, whose line runs down into the parent's lane and back into the box: return the signed form. The diamond's line marked yes runs right to a box: record consents, whose line runs up into the teacher's lane to an oval: trip list fixed. teacher schooloffice parent tripplanned write theletter andform copy andsend formshome read theletter return thesignedform all formsback by thedeadline? no send areminder yes recordconsents trip listfixed

Thinking in Diagrams

Field guide

BPMN

A resident reporting a pothole to the town council, in BPMN One pool, named town council in a band at its left, holding three lanes, one above another, each named at its left with no line between its name and its tasks: customer services, highways inspector, repair crew. Tasks are rounded boxes, joined in order by sequence flows, lines with arrowheads; no event is drawn. In customer services, a task: log the report; its sequence flow runs down into the highways inspector's lane to a task: inspect the road, whose sequence flow runs right to a gateway, a diamond with an X inside, labeled repair needed? Its sequence flow marked no runs up into customer services to a task: tell the resident why not, where that path ends. Its sequence flow marked yes runs right to a task: decide how urgent, whose sequence flow runs down into the repair crew's lane to a task: schedule the repair, whose sequence flow runs right to a task: fill the pothole, whose sequence flow runs up into customer services to a task: tell the resident it is fixed, where that path ends. towncouncil customerservices highwaysinspector repaircrew log thereport inspectthe road repair needed? no tell theresidentwhy not yes decide howurgent schedulethe repair fill thepothole tell theresident itis fixed

Thinking in Diagrams

Field guide

Value stream map

A café's coffee order from the queue to the cup, as a value stream map Every time and count is illustrative. Top right, a factory outline with a saw-tooth roof: customers, with a box beneath it: 1 order a minute at the peak. A thin line with an arrowhead, spoken order, runs left from the customers to a box at the top: till. From the till a thin line with an arrowhead, name and drink on the cup, runs down to the second step. Along the middle, left to right: a triangle marked I, 4 people queuing; a process box, order and pay, with a box beneath it: cycle time 40 s; a FIFO lane, two ruled lines marked FIFO, 3 cups waiting; a process box, make the drink, with a box beneath it: cycle time 55 s; a triangle marked I, 1 drink on the counter; a process box, hand over, with a box beneath it: cycle time 10 s, and from its top a broad outlined arrow up to the customers. Along the bottom, the timeline, a square wave: its troughs, the waits, 4 min, 3 min and 1 min; its peaks, the work, 40 s, 55 s and 10 s. Beneath it: about 10 min from queue to cup, under 2 min of it work. customers 1 order a minuteat the peak spoken order till name and drinkon the cup I 4 peoplequeuing orderand pay cycle time40 s FIFO 3 cupswaiting make thedrink cycle time55 s I 1 drink onthe counter hand over cycle time10 s 4 min 40 s 3 min 55 s 1 min 10 s about 10 min from queue to cup, under 2 min of it work

Thinking in Diagrams

Field guide

Service blueprint

A haircut at a barber's, as a service blueprint Four columns, left to right in time, and five rows, each named at its left. Physical evidence, in boxes: barber's pole, shop window; waiting chairs; mirror, cape and clippers; card reader. Customer actions, in boxes: walk in; wait for a chair; describe the cut and sit; pay and leave. Then a ruled line across: line of interaction. Onstage, in boxes: greet and take a name, under walk in; ask what cut, cut the hair, under describe the cut; take payment, under pay and leave. Then a ruled line across: line of visibility. Backstage, in a box under wait for a chair: sweep the floor, clean the clippers. Then a ruled line across: line of internal interaction. Support processes, in a box under pay and leave: card payment system. Lines with arrowheads: from walk in down to greet and take a name; between describe the cut and ask what cut, with an arrowhead at each end; between pay and leave and take payment, with an arrowhead at each end; from take payment down to the card payment system; and from sweep the floor, clean the clippers, right and up to ask what cut, cut the hair. physicalevidence barber's pole,shop window waitingchairs mirror, capeand clippers card reader customeractions walk in wait fora chair describe thecut and sit pay andleave line of interaction onstage greet andtake a name ask what cut;cut the hair takepayment line of visibility backstage sweep thefloor, cleanthe clippers line of internal interaction supportprocesses card paymentsystem

Thinking in Diagrams

Field guide

Customer journey map

Buying a secondhand car, as a customer journey map At the top, a box: actor, a first-time buyer on a fixed budget; scenario, buying a secondhand car, expecting a fair price and no hidden faults. Beneath it, a grid of five rows, each named at its left, and five phases as columns, left to right: set a budget; search listings; view and test-drive; negotiate and pay; register and drive away. Actions, phase by phase: check savings; filter by price and mileage; inspect, drive, ask for the service history; haggle, pay; transfer the registration, insure. Mindsets: what can I afford?; is this mileage normal?; has it been in a crash?; am I paying too much?; did I miss something? Emotions, between delighted at the top and frustrated at the bottom: one line with no arrowhead, middling at the budget, rising while searching, falling at the viewing, lowest at negotiating, and highest driving away. Opportunities: a history check before viewing, under view and test-drive; a price guide before haggling, under negotiate and pay. actor: a first-time buyer on a fixed budgetscenario: buying a secondhand car, expecting a fair price and no hidden faults phases set a budget searchlistings view andtest-drive negotiateand pay register anddrive away actions checksavings filter by priceand mileage inspect, drive,ask for theservice history haggle,pay transfer theregistration,insure mindsets what can Iafford? is thismileage normal? has it beenin a crash? am I payingtoo much? did I misssomething? delighted emotions frustrated opportunities a history checkbefore viewing a price guidebefore haggling

Thinking in Diagrams

Field guide

Theory of change

Clean cookstoves to cut illness from indoor smoke, as a theory of change Five rounded boxes, each an outcome, joined by lines with arrowheads pointing up to the outcome each must come before. At the top, the long-term outcome: fewer deaths and illnesses from household smoke. Beneath it: women and children breathe less smoke at home. Beneath that: households cook every meal on a clean stove or fuel. Beneath that, side by side: households can afford a clean stove and its fuel, whose line up carries a small box numbered 1; and stoves meeting WHO's emission targets are sold locally, whose line up carries a small box numbered 2, with a small circle lettered A at its top left corner. Beneath them, a key: box 1, a subsidy for a clean stove and its fuel; box 2, certifying stoves to WHO's emission targets; circle A, stoves meeting WHO's emission targets exist. fewer deaths and illnessesfrom household smoke women and children breatheless smoke at home households cook everymeal on a clean stove or fuel households can afford aclean stove and its fuel 1 stoves meeting WHO's emissiontargets are sold locally A 2 1 a subsidy for a clean stove and its fuel 2 certifying stoves to WHO's emission targets A stoves meeting WHO's emission targets exist

Thinking in Diagrams

Field guide

Decision tree

A farmer deciding whether to cut hay before forecast rain, as a decision tree Read left to right. The words cut today?, then a small square, the decision. Two branches leave it. The upper branch, cut, runs to a small circle, a chance point, with two branches of its own: rain on the cut hay, probability 0.4, ending at a small triangle beside the words about 22% lost, poorer feed; and no rain, probability 0.6, ending at a small triangle beside the words about 6% lost. The lower branch, wait, ends at a small triangle beside the words cut after the rain, the crop a few days older. No branch has an arrowhead. cut today? cut rain on the cut hay (0.4) about 22% lost, poorer feed no rain (0.6) about 6% lost wait cut after the rain,the crop a few days older

Thinking in Diagrams

Field guide

Stakeholder map

A proposed community wind turbine on a hill above a village, as a stakeholder map A grid of two axes at a right angle: interest up the left side, low to high, and power along the bottom, low to high, each axis divided at its middle by a line across the grid, making four quadrants. Top left, subjects: nearest residents, and the bird and bat society. Top right, players: the local planning authority, and the landowner. Bottom left, the crowd: weekend walkers. Bottom right, context setters: the airport radar operator, and the electricity network operator. No line joins two parties. high interest low low power high subjects players crowd context setters nearest residents bird and bat society local planning authority landowner weekend walkers airport radar operator electricity networkoperator

Thinking in Diagrams

Field guide

Capability map

A city zoo, as a capability map One large box, city zoo, holding three rows of boxes, each row a tier named at its left. Strategic: conservation planning; licensing and inspection. Core: animal care, a box holding three smaller boxes, husbandry, veterinary care and nutrition; then conservation breeding, public education and visitor admissions, one above another. Supporting: collection records; escape prevention; pest control. No lines join the boxes. city zoo strategic conservationplanning licensing andinspection core animal care husbandry veterinarycare nutrition conservation breeding public education visitor admissions supporting collectionrecords escapeprevention pest control

Thinking in Diagrams

Field guide

Risk bow-tie

A mine's tailings dam failing, as a risk bow-tie Read left to right through a knot in the middle. Above the knot, the hazard: wet tailings behind an earth dam above a village and a river, joined by a plain line down to the top event at the knot: the dam breaches. On the left, three threats, each on a line running right to the top event, with a prevention barrier across it: flood water overtops the dam, barrier water kept off the tailings; an earthquake beyond the design, barrier built by the downstream method; seepage erodes the dam, barrier drains kept clear and seepage watched. On the right, two lines run from the top event to two consequences, each with a mitigation barrier across it: barrier sirens and an emergency plan, consequence deaths in the village; barrier emergency storage downstream, consequence a river poisoned far downstream. No line has an arrowhead. wet tailings behind an earth damabove a village and a river the dambreaches flood waterovertops the dam water kept offthe tailings an earthquakebeyond design built by thedownstream method seepageerodes the dam drains kept clear,seepage watched sirens and anemergency plan deaths inthe village emergency storagedownstream a river poisonedfar downstream

Thinking in Diagrams

Field guide

Wardley map

A community radio station, as a Wardley map Up the left side, visible at the top and invisible at the bottom; along the bottom, evolution in four stages, genesis, custom built, product (+rental) and commodity (+utility). At the top, the anchor: listeners, joined by a plain line to the small circle of their need, local shows, custom built. Plain lines run down from local shows to the components it needs: volunteer presenters, custom built; a studio, a product; a community radio licence, custom built; an FM transmitter, a product; and an internet stream, a product. The studio needs playout software, a product; the FM transmitter needs mains power, a commodity; the internet stream needs an internet connection, a commodity. From the internet stream, a line with an arrowhead points right, toward commodity: its expected move. visible invisible genesis custom built product (+rental) commodity (+utility) listeners local shows volunteer presenters studio community radio licence FM transmitter internet stream playout software mains power internet connection