Cost and Speed of a Workflow

Every step is one more run of the AI, and a run takes time and, in some tools, counts against a limit or a bill. Three things set the total: how many steps there are, how much text each one reads, and how often anything repeats. Count them before you build.

What goes in

Every step reads what you hand it, in full, every time. A long input is paid for in each step that carries it.

Where the Cost and the Time Come From

1Steps: each is a run and a waitA workflow of four steps is four runs, one after another. A short job does not need a long chain.
2Length: the words are read every timeWhatever you hand a step is read in full. When the next step needs only the table, hand it the table and not the whole document.
3Repeats: they multiplyA loop, several versions or a step for each part of a split file run again and again. Set the number first: two tries, three versions, no more than ten parts.
4Checks: a rule is free, a second look is a runA plain rule runs with no AI at all. A second look by the AI is another run, and a person looking takes your time. Use a rule wherever one can do the job.
5Speed: steps wait on each otherA step that needs the one before it waits for it. Steps that do not depend on each other, like the parts of a split file, can run side by side in an automation tool; in a chat they run one at a time.

Worth the Cost, or Trim It?

For each choice, decide whether it earns its cost or should be trimmed.

1
A plain rule that checks every number in a summary appears in the document.
2
The full 60-page report is pasted into all four steps, but only step 1 reads it.
3
A loop that runs until the check passes, with no limit.
4
Three versions of the opening line of a donor appeal, rated against criteria.
5
A second look by the AI after every step, where a plain rule could make the same check.
6
A person reads the one judgment no rule can make: is the summary fair to the report?

0 of 6 answered.

Counting the Runs

Five common shapes, with the runs they take and one way to keep each down.

For each	Runs	What is read	Keep it down
Three steps in a row	Runs: Three, one after another.	What is read: Each step reads its own input and the step before it.	Keep it down: Hand on only what the next step needs.
Split a long file	Runs: At least three: map, summarize the parts, merge.	What is read: The file once to map, then its parts, then all the notes to merge.	Keep it down: Cap the parts, and keep each part’s notes short.
A loop with a limit of two	Runs: One, and one more only if the check fails.	What is read: The second try also reads what the check found.	Keep it down: Write a check that says exactly what failed, so one more try is enough.
Best of three versions	Runs: Three: write the versions, rate them, pick one.	What is read: All three versions are read at the rating.	Keep it down: Write the versions in one step, not one run for each.
A person looks	Runs: None.	What is read: Your time: a few minutes at the end.	Keep it down: Put the look last, after the rules, so you read only what passed.

Go Deeper

Lesson 9: Testing a workflowRun a test set and count what each run took.Split and merge, the parts guideWhere a long file’s cost goes, drawn with a real template.Choosing a workflow shapeThe simplest shape that does the job is also the cheapest.