Inventory Optimization ProAdvisory by Sharon Custer Free 30 minutes

The 30-Day Numbers That Hold Challenge

The stock report says one inventory value. The books say another. The AI summary never noticed.

30 days to an inventory number that holds.

30 AI workouts on the IOP method: the same 5 stages every diagnostic runs, from the first data entry to the one page the owner acts on. Every workout ends on a number that must match.

AI does not fix a wrong inventory number. It makes it look finished.

Start the challenge

Sharon Custer

Built by Sharon Custer. Operational finance, Fortune 500 inventory finance at 3M, then CFO and FP&A roles.

01

A method, not a pile of prompts

30 workouts in the order the money moves. Stage 1 proves the number. Every stage after it stands on the one before. No forecast is better than the data under it.

02

A right answer, every day

Everyone works the same practice distributor, so every workout ends on a number that must match. Nobody has to wonder whether the AI got it right.

03

Then your own numbers

Run the same workout on your company's exports. Where your data disagrees with the answer is where the cash is, and it is yours to find.

Day 1 to day 30

From checking the inventory number to proving it.

Day 1Day 30
Checks every AI answer by hand, the night before.→Knows the AI got it right, because the number matches.
Reports the inventory number the system gives.→Proves it before anyone uses it.
Explains a margin move as timing.→Shows why margin moved, in dollars.
Celebrates the bestseller by revenue.→Knows which product is holding the cash.
Finds the bad purchase after it lands.→Tests the purchase before it is signed.
Answers "where did this number come from?" with "let me check".→Opens the source.

6 questions on day 1. The same 6 on day 30.

Answer them about your own company before workout 1. Answer them again after workout 30, with the source for each.

  1. What is our inventory value, and does every report agree?
  2. Which date decides the month a cost lands in: the purchase order, the receipt or the invoice?
  3. Why did margin move last month, in dollars?
  4. Which product holds the most cash, and how many times did it turn last year?
  5. Which week does the cash for the next large purchase actually leave?
  6. Who owns the inventory number between month ends, by name?

The IOP method

5 stages. The path every inventory dollar takes, and where each one hides cash.

6 workouts a stage, all 30 open the day you join. The 6th workout of each stage is the stage's build, and it comes with the worked answer.

1

Accounting data accuracy

Prove the number before anyone uses it.

Where cash hides

Cost landing in the wrong period, absorbed as an adjustment every month.

Walk away with

A data issue log: every issue, its dollar effect, and its owner.

Trust the close
2

Operations and inventory management

Price the costs margin is quietly carrying.

Where cash hides

Shrink, rework and returns that nobody prices, so margin carries them quietly.

Walk away with

A COGS check that reruns every month.

Trust the close
3

Inventory analysis and KPIs

Name the products holding the cash.

Where cash hides

The bestseller by revenue that turns 1.5 times a year and parks the capital.

Walk away with

Every product ranked by the cash it holds, with what to act on today.

Find the cash
4

Planning and financial modeling

Test the purchase before it is signed.

Where cash hides

Purchases committed before the cash arrives, covered by the credit line.

Walk away with

A purchase test for every order over a set amount: forecast, first order, cash timing.

Find the cash
5

Reporting and strategic planning

Put the answer on one page the owner acts on.

Where cash hides

Reports that land after the decisions, so this month is run on last month's numbers.

Walk away with

A one-page executive summary and action plan, every number traced to its stage.

Get the report

What day 30 looks like

5 working tools, and one number nobody had found.

Every stage leaves something that runs again next month. Together they are an inventory finance system, built by the person who runs it.

The data issue log

Every issue in the inventory data, its dollar effect and its owner.

The monthly COGS check

Margin that holds, because the cost behind it is checked every month.

The cash ranking

Every product ranked by the cash it holds, with what to act on today.

The purchase test

Every large order tested for demand, first-order size and cash timing before it is signed.

The one-page summary

The owner's page: what changed, what it costs, who acts, every number traced.

The gap in your own data

Run on your own exports, the stage 1 workouts find where your numbers disagree, in dollars. That is the number to walk in with.

Practice on a real business. Then switch to your own.

The practice company

A sample distributor with products, purchase orders, sales and stock on hand. The same 4 exports every IOP diagnostic starts from.

The answer

Each workout ends on a number that must match. Each stage's build comes with the worked answer and a checklist.

Your own numbers

Every workout runs again on your own exports. The same steps, the same checks.

Join

One price. The whole method.

The Numbers That Hold Challenge

US$497

  • All 30 workouts, open the day you join
  • The practice company: 22 files, one download
  • Copy-paste prompts, and a number to match at the end of every workout
  • A worked answer for every workout
  • The column map and matching prompt, so every workout runs on your own data
  • Keep every workout, prompt and template

Start the challenge

When your numbers disagree with the answer

That gap is where the cash is.

The practice company has a right answer. Your own data will not always agree with it. A private coaching session takes the question your data raised, on your own numbers, in your own Claude. US$575 for the session.

Book a private coaching session

Built for

  • Controllers, finance managers and FP&A at distributors and manufacturers
  • CFOs and owners who want to build it themselves
  • Fractional CFOs with inventory-heavy clients
  • Anyone already using Claude or ChatGPT on finance work

Not built for

  • First contact with AI tools
  • Ecommerce and direct-to-consumer brands
  • General FP&A topics: headcount, sales pipeline, HR

Who built it

Sharon Custer

My career has been in operational finance, including Fortune 500 inventory finance at 3M, then CFO and FP&A roles across several industries. I have been the operator, the CFO and the person who had to defend the number in the room.

Today I build working Claude workflows for financial and inventory analysis, I coach inside the AI Finance Club, and I am a registered Cin7 implementation partner.

Every workout in this challenge comes from a workflow built for real inventory work. I work from Costa Rica, in English and Mandarin.

Questions

Before joining

Which AI tool?

Claude. Most workouts also run in ChatGPT, and the checks work in any tool.

Is coding needed?

No. Plain instructions, spreadsheets and Claude. Nothing to install.

When do the workouts open?

All 30 open the day you join, on one private page. One a day works best: 30 days, or faster if you like.

What if a day gets missed?

Everything stays on your private workout page. Pick up where you stopped.

Does anyone check my work?

The answer does. Every workout ends on a number that must match, and every stage's build comes with the worked answer. To have your own company's numbers looked at, book a private coaching session.

Is company data safe?

Every workout runs on the practice company. Switching to your own exports is your choice, and stage 1 shows how to keep company numbers separate.

Day 30

Walk in and defend every inventory number in the room.

Where it came from, what was checked, and why it holds.

Start the challenge