Practical Decision Models for Everyday Choices at Work

Most of us carry two or three decision tools and use them for everything: a pros and cons list, a two-by-two grid, a gut feeling with a spreadsheet attached. They work until the decision is a different shape. A choice you cannot reverse needs different handling from one you can. So does a choice between five reasonable options, or a project you have already spent a lot on.

A decision model is only a question asked in a fixed way. Its value is that it makes you look at something you would otherwise skip. Below is a small working set for ordinary choices at work, grouped by the question each one answers. They are drawn from my book Top 100 Decision Models for Strategic Thinking, and none needs more than a sheet of paper.

What should I do first?

Start with the Eisenhower Matrix, which sorts work by two qualities that people habitually blur: how much a task matters and how soon it demands attention. It takes its name from Dwight Eisenhower, who in a 1954 speech drew a line between urgent and important problems and remarked how rarely the two coincide. The practical use is simple. Take today's to-do list, mark each item urgent, important, both or neither, then put one important-but-not-urgent item in your diary before lunch. That last category is the one that never gets done by itself.

The Pareto Principle is the observation that a minority of inputs tends to produce a majority of results. The famous 80/20 split is shorthand, not law; real data might come out at 70/30 or 95/5. For a recurring annoyance at work, list every cause you can think of in two minutes, circle the two you suspect produce most of it, and note what data would confirm it.

Then there is the cost that never appears on the list.

The real price of any choice is the best thing you gave up to make it.

Opportunity cost is the value of the best alternative you give up when you choose something. It is among the first ideas taught in any economics course, and among the first forgotten in any planning meeting. Look at the biggest commitment in your diary this week and write down, in one line, the single best thing you could do with that time instead.

For a team, the question becomes where the work is stuck.

A team can be busy all day and still finish almost nothing.

The usual cause is not laziness but too many things started at once. Kanban treats that as a flow problem and limits how much may be in progress. Its relative, the Theory of Constraints, holds that the output of any system is limited by one bottleneck at a time, and that improving anything other than that bottleneck is largely wasted effort. Ask where work most often sits waiting. That is the step to fix.

Can this be undone?

Before deciding how carefully to decide, check what kind of decision it is. In his letter to Amazon shareholders published in 2016, Jeff Bezos divided decisions into two types. Type 1 decisions are consequential and irreversible, or nearly so: walk through the door and you cannot get back. Type 2 decisions are changeable: if you dislike what you find on the other side, you can step back through.

The image of one-way and two-way doors is useful because it stops you spending a week on something that could be reversed in an afternoon. List the five decisions waiting on your desk, mark each one-way or two-way, and make one of the two-way ones before lunch.

For the one-way doors, slow down and use two more tools.

The pre-mortem, described by the psychologist Gary Klein in 2007, moves the post-mortem to the moment it can still help: before the project starts. It draws on the finding that people come up with explanations more readily for an event imagined as having already happened than for one framed as merely possible. Set a three-minute timer, write "It failed because…" at the top of a page and fill the page.

Margin of safety is the engineer's instinct applied to commitments. A bridge expected to carry ten tonnes is built to carry several times that, because loads, materials and calculations all contain error. The principle is to leave room for being wrong. Write your realistic worst-case estimate beside the commitment you are about to make, and check that what you are promising sits clearly inside it.

How do I compare the options?

When there are several options and several things you care about, the Weighted Decision Matrix compares the options against each criterion, with each criterion carrying a weight that reflects how much it matters. It is common in engineering, procurement and public bodies, where decisions need to be explained as well as made. The step that keeps it honest is the order: write down three criteria and give them weights that add up to 10 before you score a single option. If you set the weights afterwards, you will set them to suit the answer you already wanted.

When the outcomes are uncertain, use expected value: the average result of a choice if you could make it many times over. The idea comes from a 1654 exchange of letters between Blaise Pascal and Pierre de Fermat about how to split the stakes of an unfinished game of chance. Give each option a best and a worst outcome with rough odds, work out the expected value of each, and see whether the ranking surprises you.

When the difficulty is your own mood, the 10/10/10 rule, set out by Suzy Welch in 2009, asks how you will feel about each option in ten minutes, in ten months and in ten years. The numbers are not magic. They are a device for dragging attention away from the present moment, where emotion tends to dominate, towards the stretches of time where most consequences live.

Which traps should I check for?

Some models exist to stop a specific mistake.

The sunk cost trap. Costs that have already been paid and cannot be recovered should play no part in deciding what to do next. The money is gone whichever path you choose. People find this remarkably hard to apply. For a project you are still funding, write two lines, one for continuing and one for stopping, using only costs and benefits from today onwards.

Goodhart's Law. A measure stops being reliable once it becomes a target. Pick one target your team is judged on and spend three minutes writing the easiest way someone could hit it without helping anyone. If the answer is easy, add a counterweight.

Chesterton's fence. From a 1929 essay by G. K. Chesterton about a reformer who wants to clear away a fence he sees no use for. The principle is not a defence of everything old. It is a rule about the order of operations: understand first, change second. Before removing a rule nobody can justify, ask the person who has been around longest what went wrong before it existed.

Inversion. Most planning runs forwards. Inversion asks what would guarantee that we miss the goal. Write five ways to make sure this month's goal fails, and circle the one you are closest to doing already.

How will I know whether I decided well?

A good outcome does not prove a good decision, and memory rewrites the reasons afterwards. The fix is unglamorous.

Write it down before you know how it turns out.

A decision journal is a written record made at the moment of choosing: what you decided, why, what you expected and how you felt. It grew up in investment firms, where the gap between good decisions and good outcomes is painfully visible. Five lines will do: the choice, the reason, what you expect, how confident you are as a percentage, and a review date in your calendar.

For work done with others, the After-Action Review does a similar job. It is a short, structured conversation, developed by the US Army in the 1970s for training exercises, that captures what a team learned while it is still fresh. End it by circling the single change you will make next time.

What to take from this

• Separate urgent from important, and book time for one important thing that is not urgent.
• Count what you give up as part of the price of any choice.
• Find the one step where work waits, and limit how much is started at once.
• Decide quickly when you can step back through the door, and slowly when you cannot.
• Imagine the failure before you begin, and leave room for being wrong.
• Set your criteria and weights before you score the options.
• Ignore costs already paid. Judge from today onwards.
• Record the decision and your reasons before you know the result.

These are a dozen or so models out of a much larger set. Top 100 Decision Models for Strategic Thinking: One hundred ways to think before you choose gives each of its hundred models a worked example, a note on where it misleads and a two-minute exercise, with a labelled diagram in every chapter. It is a 314-page PDF and costs £9 on Gumroad: https://matsiems.com/books/top-100-decision-models.