H1 Trim out the harm

Remove components that have harms associated with them by understanding all the actions delivered by the component, both good and bad. Then transfer the useful actions to other parts of the system, allowing the component to be removed: creating a simpler system of fewer components that delivers all useful actions with fewer harms (and associated costs). Trimming is typically performed after a Function Analysis (Chapter 12) has been completed.

Start by trimming components that

• Are long way from the Prime Output
• Have lots of harmful actions
• Are expensive or unnecessarily complicated

Before transferring the useful actions, ask whether you need the object of the useful action. If the object is not required, you can trim both the subject and the object.

H1.1 Do we need the useful action of the component? If not, remove the component.

H1.2 Could the object perform the useful action? If yes, trim the subject and transfer responsibility for the useful action to the object.

H1.3 Could another component perform the useful action? If yes, trim the subject and transfer responsibility for the useful action to the other component.

H1.4 Could a resource perform the useful action? If yes, trim the subject and transfer responsibility for the useful action to the resource.

H1.5 Could we trim the subject after it has performed its useful action? If yes, trim the subject in time.

H1.6 Could we partially trim any harmful parts but leave any useful parts? If yes, trim in space: remove only the part of the subject that is delivering the harmful action, or only the part of the object that is receiving the harmful action.

H2 Block the harm

H2.1 Counteract the harmful action with an opposing field that neutralises the harm. For example, refrigerator keeps food cool in hot weather; noise-cancelling headphones work by producing a noise-cancelling wave that is 180° out of phase with the ambient noise.

H2.2 Change the object so it is not sensitive to the harmful actions. For example, add vents in an umbrella so wind doesn’t make it turn inside out.

H2.3. Change the zone and/or duration of the harmful action to decrease its effects. For example, reduce the harmful effects of X-rays by giving the minimum effective dose required to obtain a clear image, in only the place that it is needed.

H2.4 Insulate from the harmful action by introducing a new component or substance; this can be made from elements of existing components that can be modified (including voids, bubbles, foam and so on). For example, rind on cheese; use surgical gloves to prevent infecting patients.

H2.5 Introduce a sacrificial substance to absorb the harm. For example, bumpers on cars; steel mesh balls in kettles to attract limescale and prevent build-up on the heating element.

H2.6 If a required action harms the system, apply it indirectly via a linked element. For example, oven gloves; melt chocolate in a bain marie (double boiler).

H2.7 Protect part of the system from harm; for example, lead aprons during X-rays.

H2.8 Reduce the harm by using a weaker action and enhancing it only where needed. For example, knowledge speed cameras may be present on roads reduces driver speeds generally: actual cameras are placed at accident black spots to reinforce the effect.

H2.9 Use sub-systems/details of components to stop the harm. For example, silver used in socks to kill odour-causing bacteria.

H2.10 Use super-systems/the environment to stop the harm. For example, air conditioning to cool rooms that contain a lot of computer equipment.

H2.11 Switch off the harm. For example, remove magnetism of steel tools; medication that doesn’t allow absorption of fat from food ‘switches off’ the harm of fat.

H3 Turn the harm into good

H3.1. Use the harm to deal with the harm. For example, vaccination (small component of a virus stimulates immune response); deliberately burning a strip of land ahead of a wildfire.

H3.2 Use the harm for something good. For example, use waste food and grass cuttings for compost; stress of exams promotes hard work and learning material.

H3.3. Add another harm so that the combination of the two harms is no longer harmful. For example, add a strong alkali to a strong acid to neutralise.

H3.4 Amplify the harm until it delivers a benefit. For example, extinguish an oil well fire by creating an explosion at the well head. This momentarily consumes the atmospheric oxygen and puts out the fire; encourage extremist politicians to air their views on every topic to make their extremism very clear.

H4 Correct the harm

H4.1 After a harmful action has happened, eliminate any of its harmful consequences. For example, kitchen paper towels to mop up spills; after a traumatic event, seek counselling to mitigate long-term psychological impact.

H4.2 Counteract or control the harmful effects from a harmful action – either during or beforehand. For example, pre-stressed concrete; training for front-line emergency staff in dealing with difficult/violent people.

H4.3 Predict and eliminate harms before they happen, use something that disappears or becomes part of the system/environment. For example, use ice instead of sand for cleaning buildings; prevent potential damage from removing stitches by using dissolvable stitches in wounds.

i1 Add something to the subject or object

i1.1 Add something to or inside the subject or object to enhance the function. The additive can be permanent or temporary (if temporary it disappears or decomposes after use). For example, metal skewers in baking potatoes to help heat reach the middle of the potato.

i1.2 Add something between the subject and object which enhances the function. For example, spectacles to enhance eyes; wrapping baking potato in foil to speed up cooking; shoe horn.

i1.3 Use the external environment to enhance/provide the functions. For example, fluoride in drinking water.

i1.4 Change or add something to the environment/surroundings of the subject and object. For example, add smoke to wind tunnel to monitor air flow around an object more effectively.

i1.5 Add something outside/around the subject and object to change the features/properties of the subject or object or provide extra functions such as protection. For example, sugar coating on chocolates to prevent melting.

i1.6 Add something from the environment/surroundings to enhance the function. For example, sea water used as ballast in ships.

i1.7 If we can’t add anything, use the deterioration or decomposition of the components/environment to enhance the function. For example, green patina caused by oxidation protects copper roofs from further wear; use the two halves of a broken eggshell to help separate white from yolk.

i2 Evolve the subject and object

i2.1 Segment the subject or object; increase the degree of fragmentation/divide into smaller units. For example, multiple cylinders in internal combustion engines; grind coffee beans.

i2.2. Introduce voids, fields, air, bubbles, foam or similar into the subject or object. For example, wetsuits trap water to provide insulation; bubble wrap; duvets.

i2.3 Improve systems by multiplying similar system elements, or combining with another similar system to improve actions; add new dissimilar elements to provide extra functions which will become integrated as the system evolves. For example, to TVs add speakers, DVD players, digital TV boxes, streaming capability from other devices; Swiss army knife; combined washing machine and dryer.

i2.4 Make the system more flexible/adaptable/dynamic. For example, business reorganisation from monolithic to smaller, focused business units; expanding via franchising, licensing and partnering on specific projects; cut-to-size insoles for shoes; clingfilm.

i2.5 Develop the links between the system elements (make them more flexible or more rigid). For example, snow chains on car tyres; Rubik cube.

i2.6 Increase the difference between elements. For example, seek out diverse employees (age, experience, background) to get a varied workforce with a wider spread of ideas.

i2.7 Separate by scale; provide opposite functions at different levels. For example, a bicycle chain has rigid components to transmit force but the system as a whole is flexible.

i2.8 Transition function delivery to the micro-level. For example, self-cleaning glass; microcapsules in cosmetics; microwave ovens.

i.2.9 Improve controllability by developing a component or part of the system to deliver additional useful functions. For example, central heating thermostat that incorporates a timer to give different set points at different times (such as cooler overnight).

i2.10 Improve a system by changing components/substances to deliver exactly what is needed in time and/or space. For example, Direct Line Feed: component suppliers deliver parts directly to a customer’s production line.

i.a. Improve the action

These solutions help us get the right action and get the action right; they are useful when we need either to improve an existing action or to get an action that is currently missing.

i.a.1 Add a missing action; also add a subject if required. Look in the TRIZ Effects Database if required. For example, find a way of chilled food telling us it is still safe to eat (more precisely than use-by dates); add wings to F1 racing cars to provide downward force and increased cornering grip.

i.a.2 Add another action from existing components. For example, sonic toothbrushes use sound waves as well as mechanical vibration to clean teeth.

i.a.3 Change the action to a better one. For example, induction hobs use electromagnetic induction to heat pans rather than thermal conduction, providing more efficient and safer heating.

i.a.4 Change from a uniform action to an action with predetermined patterns. For example, pressure washer hoses pulse water to improve cleaning.

i.a.5 Match or mismatch the natural frequency of actions with the natural frequency of the subject or the object. For example, hot desk part-time employees.

i.a.6 Match or mismatch the frequencies of different actions. For example, a production line of different people doing different actions works much more efficiently than everyone working in parallel.

i.a.7 To achieve two incompatible actions, perform one action in the downtime of the other. For example, maintenance and cleaning of office buildings at night.

i.a.8 Use existing actions/fields to create other actions/fields. For example, use the heat from lightbulbs to heat a cold bathroom.

i.a.9 Use actions that exist in the environment (such as gravity, ambient temperature, pressure, sunlight). For example, solar-powered torches.

i.a.10 Get another action from any available resources such as other components in your system, or the environment. For example, use your smartphone to control your home heating.

i.a.11 Use excessive action and remove the surplus. For example, overfill pints of beer to ensure a creamy head of foam and remove the excess.

i.a.12 Use a small amount of a very active additive. For example, stain removing powders added to clothes washes.

i.a.13 Concentrate the additive at a specific location. For example, spot treatment of stains on clothing.

i.a.14 Introduce an additive temporarily. For example, flavour stews with herbs in a muslin bag, which can be removed.

i.a.15 Use a copy or mode of the object in which additives can be used, instead of the original object, if additives are not permitted in the original. For example, electronic cigarettes.

i.a.16 Improve an action by changing the phase of the existing action or component (use solid, liquid or gas of the same material). For example, steam cleaning; transport natural gas as a cryogenic liquid.

i.a.17 Achieve an action by using phenomena that accompany phase change. For example, split rocks by filling with water then reducing temperature below zero: they crack when the water turns to ice.

i.a.18 Achieve an action with dual properties by using components capable of converting from one phase state to another. For example, shape-memory metal heat exchangers.

M1 Indirect methods

M1.1 Change the problem so there is no need for measurement or detection. For example, cooking in boiling water doesn’t require measuring temperature: boiling water is always at 100°C.

M1.2 Measure a copy or image. For example, use photos or mirrors; ultrasound scans are used to measure the size of growing foetuses; barcodes and scanners to give product prices.

M1.3 Change the problem into detecting or measuring a number of consecutive, successive changes. For example, calculate when the Big Bang happened from the current distance and velocity of galaxies.

M2 Add something

M2.1 Add something and then measure changes to one of its features. For example, there are egg timers that you place in the same saucepan of water as your egg, which change colour to tell you when the egg is cooked; car tyre tread-wear indicators.

M2.2 Add something made from an extra/new component, which creates a field. For example, Mercaptan (a substance that smells strongly of rotten eggs) is added to natural gas (which is odourless) to enable leak detection.

M2.3 Add something to the environment around our system that reacts to what you want to measure. For example, put leaking bicycle tyre in water to find leak.

M2.4 Create additives in the environment by decomposing or changing the environment. For example, track location of aeroplanes from vapour trails.

M3 Enhance measurement with fields

M3.1 Use the natural phenomena that are already a part of our system; utilise the scientific/physical effects to observe changes. For example, measure human body temperature by measuring intensity of the emitted infrared radiation; when boiling sugar, observe the different characteristics of the sugar (soft-ball, hard-ball, hard-crack and so on) to know when to stop, instead of using a thermometer.

M3.2 Use resonance or resonant frequency. For example, observe changes in the resonant frequency of a system, component or the environment that are related to what you want to measure. For example, detect cracks in bells or bowls by striking them: the note sounds different when cracked.

M3.3 Join what you want to measure to another object and measure its resonant frequency, or measure the resonance in its environment. For example, running a wetted finger around the rim of a wine glass generates a note whose pitch is related to the amount of water in the glass.

M4 Use additives with fields

M4.1 Add or make use of a substance that has a measurable field. For example, substances with magnetic fields.

M4.2 Add easily detectable substance or particles with a measurable field to your system. For example, luminous paint.

M4.3 Add easily detectable substance or particles with a measurable field inside your system. For example, put ferromagnetic particles inside your system.

M4.4 Add easily detectable particles with a measurable field to the environment. For example, throw grass in the air to measure wind speed and direction.

M4.5 Use scientific/physical effects. For example, Curie point, Hopkins, Barkhausen.

M5 Evolve the measurement system

M5.1 Go from one measurement to two or more to improve the quality of relying on a single measurement. The individual measurements may be separated

• In time (for example, use multiple measurements to compensate for an unreliable or low-resolution sensor
• In space (for example, a widely spaced array of small telescopes can obtain or exceed the performance of a single large instrument)
• By measurement type (for example, multi-spectral analysis)

M5.2 Measure indirectly from the first and then second derivatives in time or space. For example, measure distance of stars from their brightness (first derivative) and colour (second derivative). The brightness of a star is dependent on the distance from us; the colour then changes as a result of the different brightness. By identifying the colour of a star, you can work out the brightness … and from that, the distance.