The design mix: the three things a business balances in a product

1. The design mix has exactly three elements, function, aesthetics and cost, and they are settled before a single unit is made.
2. It is drawn as three overlapping circles, one labelled function, one labelled aesthetics and one labelled cost.
3. The product is marked somewhere inside those circles, sitting nearest the element its buyers care most about and further from the ones they will compromise on.
4. Where it sits is a decision rather than an accident, because the materials, the shape and the production method are chosen at the design stage and are expensive to change afterwards.

Each element in turn: what it covers and who buys on it

1. Function: how well the product does the job it is bought for, covering its reliability, its durability and how easy it is to use.
   1. A work boot is bought on function, and Dr Martens charges a premium price because its boots last through years of wear that would finish a cheap pair.
2. Aesthetics: how the product looks, feels, sounds or smells, including its styling, its finish and its packaging.
   1. A designer kettle is bought on looks, because the buyer wants an object worth leaving out on the worktop and will pay more than a plain kettle costs to get it.
3. Cost, or economic manufacture: designing the product so it can be made at a cost that still leaves a profit at the price customers are willing to pay.
   1. A supermarket own-brand cereal is designed around cost, with a simple recipe and plain packaging, so a discounter such as Aldi can price it below the branded box and still earn a profit on every one sold.
4. Cost in the design mix means the cost of making the product, not the price on the shelf, and it is fixed by design choices long before a customer sees it.

The trade-off: raising one element usually lowers another

1. The three elements pull against each other, so a gain in one is normally paid for in another.
   1. Better materials and closer engineering improve function and aesthetics, but they raise the cost of making each unit, which either forces the price up or thins the profit on every sale.
   2. Designing for cheap manufacture holds the price down, but it usually means plainer styling, lighter materials and a shorter working life.
2. A kettle maker that swaps a stainless steel body for thin plastic cuts perhaps £4 off the cost of each unit, so it can undercut rivals on price, but the kettle looks cheaper and scratches sooner, so buyers may not choose the same brand again.

Why the right balance differs by product and by market

1. There is no single correct design mix, because the balance is set by what the target market values and what it will pay.
2. One firm often designs its budget range and its premium range around different elements, and both can be right.
   1. The value range is designed around cost, using the cheapest workable ingredients and packaging so the product can land at about 89p and still return a profit.
   2. The premium range from the same firm is designed around aesthetics and function, with better ingredients and heavier packaging, because those shoppers will pay £3 or more for the difference.
3. Getting the balance wrong is expensive, because a product carrying more function than its buyers will pay for sits unsold at the price it needs, while one made too cheaply for a premium market is judged poor quality and left on the shelf.