Product business case audit practice exercise

The scenario

A B2B project management company at $12 million in annual recurring revenue, with 850 customers and an 18 percent annual churn rate, has a CFO with a standing rule: she approves product investments with a payback period under 24 months, and anything slower needs a separate conversation entirely. A senior product manager has spent two weeks building the case for an AI feature that automatically emails weekly project status summaries to stakeholders, pulling from task completion data, blockers, and upcoming milestones.

The case looks strong on its face: a 507 percent three year return and a payback period of about six months. Before it goes to the CFO, you are asked to review it. The numbers depend on several assumptions, a projected reduction in churn, a projected rate of customers upgrading to a paid AI tier, and an assumed dollar value of that upgrade, layered on top of a real engineering cost. Some of those assumptions are reasonable. At least two have a flaw that is easy to miss on a first read and hard to unsee once you spot it, not because the arithmetic is wrong, but because of what was assumed before the arithmetic started.

What you are asked to do

The exercise moves through five connected steps:

• Audit five specific assumptions in the case, classifying each as well supported, uncertain, or a red flag, and naming what evidence you would need to actually trust it.
• Identify the two assumptions with the most serious underlying flaw, name what question was never asked before the math was done, and describe what a more rigorous version of each assumption would look like.
• Recalculate the case using conservative inputs for churn reduction and expansion rate, showing the revenue retained, the expansion revenue, the total annual impact, the payback period, and the three year return, with your working shown.
• Make the launch call against the CFO's 24 month payback threshold at your conservative numbers, and name the single condition that would flip your decision in either direction.
• Write a caveat paragraph, under 100 words, naming specific assumptions by name and ending with one concrete validation action that could be completed in under four weeks.

What a strong answer covers

The exercise's own objectives set what a strong submission has to demonstrate:

• Does the assumption audit distinguish between assumptions that are actually fine and ones that are genuinely uncertain, rather than treating the whole case as either fully trustworthy or fully broken?
• Do the two flagged weak spots name the specific unasked question behind each one, rather than a general statement that the numbers seem optimistic?
• Does the conservative recalculation show its working at each step, arriving at a payback period and return that could be checked line by line?
• Does the launch decision engage honestly with the 24 month threshold at the conservative numbers, including naming what would have to be true for the decision to flip?
• Is the final caveat specific, under the word limit, and does it end in an actual, time-bound validation step rather than a general call for more data?

Skills this exercise practises

Reading a financial business case for what it assumes, not just what it calculates. Separating a reasonable assumption from an optimistic one before it reaches a numbers reviewer. Recalculating a case under a conservative scenario and still reaching a real decision instead of a hedge. Writing a caveat that adds real information rather than a vague disclaimer. These map onto the bootcamp's own curriculum on unit economics, building a product business case, and decision-making under constraints. For prioritization frameworks that inform which case gets built in the first place, see the RICE prioritization framework, and for the metrics that a case like this ultimately has to move, north star metric examples. If you want to practice the data side of a similar diagnosis, the subscription metrics case study from Data for Product Managers runs a comparable read-the-numbers exercise.

Which bootcamp this comes from

This exercise is the practical challenge from Business for Product Managers, a one week, two live session bootcamp on Builders Camp covering business model fundamentals, unit economics, pricing basics, and building a product business case. Completing the practical challenge counts toward the bootcamp's completion requirement and its certificate, alongside the certification quiz.

Builders Camp runs this bootcamp both live and self-paced, included with the Builders Camp Membership alongside every other bootcamp, track, and masterclass.