You need a function, not an object

Before buying it helps to ask:

What task is this thing supposed to solve?

Not “do I want a shelf” but “what am I going to store and how”. Not “do I need a car” but “which journeys do I have to make”. Not “do I need a new computer” but “which work is the old one getting in the way of”.

A function can often be obtained in different ways:

• buy;
• rent;
• borrow;
• order it as a service;
• use shared equipment;
• change the process;
• drop the task itself.

The best part really is sometimes the part that is not there — if its function gets performed without it. The fewer elements in a system, the fewer failures, the less servicing and the less storage space.

But the absence of a thing has a cost too.

Life without a car is wonderful where there is public transport, affordable housing and a suitable work rhythm. Somewhere else a car may be not a luxury but part of basic mobility.

Renting a tool is convenient for one job. With constant use, owning it works out cheaper and more available.

So the goal is not the minimum number of things but the minimum construction that reliably performs the functions you need.

The full cost of a thing is made up of:

• the purchase price;
• delivery;
• consumables;
• servicing;
• repair;
• storage;
• insurance;
• the time to learn it;
• the cost of disposal;
• the loss of flexibility.

Sometimes an expensive thing is cheaper to run. Sometimes a free one demands so much attention that it should have been left with its previous owner along with his good intentions.

How the task is stated changes the answer more often than it seems. Someone who “needs a printer” usually has to print a dozen pages a year: a contract, a certificate, a boarding pass. A printer for that task means cartridges drying out between uses, space on the desk and half an hour spent finding out why it is invisible on the network again. The copy shop next door solves the same task for a sum nobody bothers to count. For someone printing ten pages a day, though, that same copy shop will eat an hour a week and all their flexibility.

The same object turns out sensible or absurd depending not on the object but on the frequency. The question “is it worth buying” without an answer to “how many times a year” is not a question but an invitation to argue about taste.