The Goal and the Theory of Constraints: the five focusing steps

Who should use it, and when not to

Use it when work piles up and output doesn't grow, though everyone looks busy. Typical signs: a queue that never shrinks in front of one person or team, deadlines that slip by the same step each time, and a plan to hire or buy tools without knowing where extra capacity would help.

It fits far beyond factories. A sales team where every deal waits for the one solutions engineer, a support desk where tickets wait for the only person who can issue refunds, a content team with one editor: each has a constraint.

It is the wrong tool for choosing what to work on in the first place. If the question is which product to build or which market to enter, start with a strategy or prioritization method. It also won't help much when there is no flow at all, such as a one-off project with no repeated work.

The core concepts

The constraint. The one step whose capacity limits what the whole system delivers. An hour lost there is an hour lost for everyone. An hour saved at any other step usually just adds to a pile of waiting work. The constraint can also sit outside the team: too little demand, a supplier, or a policy.

Three measures. Goldratt judged every decision by its effect on the whole system, through three numbers:

A change is good if it raises throughput, or lowers inventory and operating expense without hurting throughput. A step that looks efficient on its own can still be bad for the system.

Drum-buffer-rope. Goldratt's scheduling method for operations. The drum is the constraint's schedule, which sets the pace. The buffer is a small stock of ready work in front of the constraint, so it never waits. The rope limits how much new work enters the system, so it matches what the drum can take.

A worked mini example

This is an illustration, not a real company. A content agency with nine people sells articles to clients. Work flows from brief, to draft (four freelance writers), to edit (one editor), to client approval. Writers produce about 30 drafts a week. The editor handles about 18. Clients want 25 a week. There are 26 drafts waiting for the editor, and they wait about eight days. About a third of drafts go back for a rewrite after editing. The editor also formats articles and answers client emails. The owner plans to sign two new clients and hire a second editor.

Identify. Editing is the constraint: it handles fewer drafts than clients need, and the queue sits in front of it.

Exploit. Add a brief checklist and a writer self-edit checklist, so fewer drafts come back for a rewrite. Move formatting and client emails off the editor. Sort the queue by deadline and fee.

Subordinate. Writers start a new draft only when the edit queue drops below a set level, and spend spare hours on rewrites. Sales checks start dates with production before signing.

Elevate. After 30 days, if output still falls short of 25, compare a part-time second editor with letting a senior writer edit short pieces.

Repeat. Once editing speeds up, client approval may become the limit. Check old rules, like weekly draft targets for writers, that only made sense before.

Notice what the plan doesn't do: it doesn't push writers to produce more. More drafts would only lengthen the queue.

How to run the five focusing steps

1. Define the goal and map the flow. Write the system's goal and one output measure, then list the steps work passes through, with capacity, queue, and wait time for each where you know them.
2. Identify the constraint. Find the step with the largest queue and longest waits, or where demand exceeds capacity. Name one, and say whether it is capacity, demand, a supplier, or a policy.
3. Decide how to exploit it. Get more from the constraint without spending: never let it wait for input, take low-value tasks off it, check quality before work reaches it, and feed it the highest-value work first.
4. Subordinate everything else. Release new work only as fast as the constraint finishes work, keep a small buffer of ready work in front of it, and accept that other steps will sometimes be idle.
5. Elevate the constraint if that is not enough. Only now add capacity, such as a hire, a tool, or outsourcing, and compare the gain in throughput with the added operating expense.
6. Go back to step 1. When the constraint moves, find the new one, and review the rules, targets, and habits built around the old constraint so inertia doesn't become the limit.

The five focusing steps skill runs this with your own numbers and marks what it can't know.

Common mistakes

• Improving everything at once. Gains away from the constraint add waiting work, not output.
• Hiring first. Exploiting and subordinating often free capacity for free. Do them, then measure.
• Keeping every person 100% busy. Steps that run flat out flood the constraint with work it can't absorb.
• Naming the constraint by opinion. Look at queues and wait times, not at who seems slow.
• Stopping after one round. The constraint moves. Rules written for the old one keep running unless someone removes them.

If the constraint turns out to be demand rather than capacity, the problem is in sales or marketing. For a sales pipeline, see sales funnel roles and stage metrics. To look at every activity a business performs, see the value chain.

Where it comes from

Eliyahu M. Goldratt developed the Theory of Constraints. He first set it out in The Goal (1984), written with Jeff Cox and published in the US by North River Press. It is a novel: a plant manager has three months to save his factory, and a former teacher helps him see it as one system. The 30th anniversary edition adds a section on the five focusing steps, which the Theory of Constraints Institute also calls the process of ongoing improvement. Goldratt's organisations went on to teach drum-buffer-rope and buffer management for operations.

This page is an independent summary in our own words. It is not affiliated with or endorsed by the author's estate, his organisations, or the publisher. Read the book for the story, which teaches the ideas better than any summary. More explainers are in the strategy books index.

Questions

What are the five focusing steps of the Theory of Constraints?

Identify the constraint, decide how to exploit it, subordinate everything else to that decision, elevate the constraint (add capacity), and, once it is broken, go back to the first step without letting old rules become the new constraint.

Does the Theory of Constraints only apply to factories?

No. Any system where work waits in line has a constraint: a sales team waiting on one solutions engineer, a support queue, an editing step in a content pipeline. The steps are the same; only the units change.

What is the main lesson of The Goal?

An hour lost at the constraint is an hour lost for the whole system, while an hour saved anywhere else changes little. So you manage the system by its one weakest link, not by keeping every step busy.