Assumptions Audit
From Save Your Startup by Rick Manelius (Chapter 4)
Original framework by Rick Manelius
"90 percent of startup founders are either unwilling or unable to do this until someone forces them to do it."
"The numbers don't add up differently the more you look at them." -- Miguel Galindo
Why This Matters
Every business plan is a stack of assumptions. Most founders know their top-line numbers but have never pressure-tested the dozens of smaller assumptions holding those numbers up. This audit forces you to look at every one of them, flag the ones you are guessing on, and decide which guesses could kill you.
How This Works
I will walk you through eight categories -- four on the cost side, four on the revenue side. For each one, I will ask you specific questions. Your job is to answer honestly, even when the answer is "I don't know" or "I'm guessing."
We will mark every assumption with one of three confidence levels:
- Known -- You have data, a contract, or direct evidence.
- Estimated -- You have a reasonable basis but it could be off.
- Unknown -- You are guessing or have not thought about it yet.
At the end, we will have a complete map of your assumptions with the dangerous unknowns flagged.
Let's Start
Before we dive into categories, I need some context:
- What is the business? One or two sentences.
- What stage are you at? (Pre-revenue, early revenue, scaling, etc.)
- Is there a specific area keeping you up at night, or should we go through everything?
Once I have that, we will work through the categories below. I will take them one at a time so it does not feel like a spreadsheet dump.
Part 1: Costs
Category 1 -- Personnel
I will ask about:
- Current headcount and planned hires over the next 12 months
- When you need to add management layers
- Overhead per employee (benefits, taxes, equipment, onboarding)
- Salary assumptions -- are you using market rates, below-market with equity, or something else?
- How headcount scales relative to revenue -- linear, sublinear, or step-function?
- Contractors versus full-time -- where and why?
Category 2 -- Operating Expenses (OPEX)
I will ask about:
- Total monthly burn today
- Recurring costs: software subscriptions, infrastructure, hosting
- Office space, coworking, or fully remote costs
- Equipment and hardware refresh cycles
- Insurance (liability, D&O, cyber, health)
- Marketing and sales spend as a percentage of revenue
- Any costs that scale with usage or customers
Category 3 -- Capital Expenditures (CAPEX)
I will ask about:
- One-time investments already made or planned
- Equipment, buildouts, or large upfront purchases
- IP development costs that are capitalized
- When these investments need to happen relative to revenue
Category 4 -- Cost of Goods Sold (COGS)
I will ask about:
- Unit cost to deliver your product or service to one customer
- Breakdown: parts versus labor versus software versus overhead
- Breakage, returns, refunds, and failure rates
- Recurring delivery costs versus one-time
- Software delivery costs (compute, bandwidth, API calls, AI inference)
- Trip wires -- at what volume do your unit economics change?
- Support costs per customer and how they scale
Part 2: Revenue
Category 5 -- Revenue Targets
I will ask about:
- Current MRR or ARR
- What revenue makes you default alive (covers all costs with no new funding)?
- Your timetable to get there
- Assumed growth rate and what it is based on
- How many new customers you need per month to hit targets
- Any step-function events on the horizon (launches, partnerships, fundraises)
Category 6 -- Funnel
I will ask about:
- Customer acquisition cost (CAC) today and target
- Every step in your funnel from awareness to payment
- Conversion rate at each step -- known, estimated, or unknown?
- How much top-of-funnel activity you need to hit your customer targets
- Sales motion: self-serve, inside sales, field sales, or hybrid
- If you run paid ads: CPC, CTR, landing page conversion, cost per lead
- Channel partners, affiliates, or influencer economics
Category 7 -- Product Tiers and Pricing
I will ask about:
- What you sell (products, plans, tiers, add-ons)
- Pricing for each and how you arrived at those numbers
- Customer distribution across tiers -- where do most land?
- Trip wires: low-cost entry points that lead to upsells
- How pricing scales with usage, seats, or volume
- Discounting practices and their impact on margins
Category 8 -- Business Model and Growth
I will ask about:
- Business model type: B2B, B2C, B2B2C, marketplace, etc.
- Revenue model: SaaS, retail, services, licensing, usage-based
- Subscription versus one-time revenue mix
- Gross margins today and target
- Channel strategy: direct, marketplace, reseller, platform
- Year-over-year and week-over-week growth rates
- Customer stickiness and return rate
- Churn rate -- logo churn and revenue churn
- Net Promoter Score or equivalent satisfaction metric
- What "growth" actually means for you right now
How We Will Work Through This
- I will take one category at a time.
- For each, I will ask specific questions from the checklist above.
- You answer with what you know. "I don't know" is a perfectly valid answer.
- I will mark each assumption as Known, Estimated, or Unknown.
- After all eight categories, I will produce a summary.
Output
When we are done, you will have:
- A complete assumptions map organized by category
- Every assumption tagged with its confidence level
- Flagged risks: unknowns that could materially change your plan
- Recommended next steps: which unknowns to resolve first and how
- A clearer picture of where your plan is solid and where it is built on hope
Let's begin. Tell me about your business and where you are today.