Scoping ML Projects
Choose the right problem before choosing the right model
Scoping decides which problems are worth ML at all, what success looks like, and who consumes the prediction. Get the scope wrong and no amount of engineering rescues the project.
What you will learn
- Judge whether a problem is a good ML fit before any training
- Translate a business metric into an ML objective
- Define a baseline and a fail-fast threshold
What is this?
Scoping frames a business need as a supervised problem: what decision needs to be made, with what inputs, against what ground truth, and with what acceptable error. A well-scoped project has a crisp success metric, a baseline to beat, a labeled-versioned data need, and a named consumer of the output.
Why do you need it?
- The majority of failed ML projects fail before any code — because the problem was unanswerable or the metric was the wrong one.
- A clear baseline (heuristic, rules, 'always predict yesterday') sets the bar a model must clear.
- Scoping forces the labeling question — who provides ground truth and at what cost — early.
- It defines the deployment shape: batch vs real-time, which directly drives the lifecycle choices.
Mental model
A restaurant deciding what to put on the menu
Scoping an ML project
You ask who the customers are, what they'll pay, whether the kitchen can even cook it, and how you'll know it sold well. Scoping is the menu decision before the chefs ever start cooking.
How it works
- Write the consumer and the decision: 'risk team uses this prediction to approve or reject a loan application.'
- Define the business metric affected (default rate, revenue) and the ML metric that proxies it (precision, AUC).
- Check data availability and label quality; if ground truth doesn't exist yet, the project is a labeling project first.
- Set a baseline — a simple heuristic — that a model must demonstrably beat.
- Agree on a fail-fast milestone: the point where you kill the project if targets aren't met.
Scoping turns a business problem into a machine learning contract.
In production
- A logistics company scoped 'predict delay' after confirming historic trip features exist; the baseline 'same truck as last week' was beaten by 12% before any deep model was tried.
- An insurance team killed a claims-fraud project at the fail-fast gate: labels were too noisy and manual review was already 94% precise.
- A bank scoped underwriting around a constrained decision (approve/reject at a fixed cutoff), making monitoring and audit immediately tractable.
Best practices
- Write the one-page scope doc: decision, consumer, metric, baseline, data need, kill point.
- Prefer a metric the business already trusts over a clever ML one.
- Plan for the cost of labels and mistakes up front — false positives and false negatives have asymmetric prices.
- Scope the smallest thing that delivers value; grow scope only after proving it.
Common mistakes
- Picking 'accuracy' when the real cost is a specific error type (false negatives).
- Scoping around the model ('let's build a transformer') instead of the decision.
- Assuming labels exist when they don't; labeling effort becomes the hidden schedule.
- No baseline, so the 'winning' model is never compared to the trivial answer.
Debugging tips
- If stakeholders argue about what the model should do, you haven't written the decision down.
- Re-read the success metric after the first data look — it often reveals the metric is unmeasurable.
- Keep a glossary of business terms; a wrong meaning quietly corrupts labels.
Interview checkpoint
Quick quiz
Which is the best first output of an ML project's scoping phase?
A project that has no measurable ground truth is a strong ML candidate because the model can 'figure it out'.