For buyers, planners and the finance team who funds them

Open to Buy Integration: Feeding the Plan With Numbers You Can Trust

Open to buy is the budget that tells a buyer how much stock they can still commit to for a period without blowing the inventory plan. The formula is simple. The hard part is the inputs: sales, stock on hand, stock on order and markdowns, all for the same period, the same stores and the same basis. In most Australian retailers those numbers live in three or four systems and reach the plan by hand on a Monday morning.

When the inputs are late or inconsistent, the plan stops being a control and becomes a spreadsheet nobody quite believes. Buyers order on instinct, cash gets tied up in the wrong stock, and the end of season clearance does the correcting. This page covers what an OTB plan actually needs from your systems, where the figures go wrong in transit, and how to automate the feed so the plan is ready before the buying meeting rather than after it.

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Realistic ROI

4 inputs

Sales, stock, on order, reductions

Every OTB method uses these, whatever the template looks like

10 percent

Error from mixing GST bases

A GST inclusive sales figure against an ex GST plan overstates sales by a tenth

1 to 2 days

Typical manual prep each week

A rough range for mid sized retailers we see, varying with store count and range size

53 weeks

Every five or six years

Week based retail calendars need a leap week, and comparisons break if it is ignored

Four Reasons OTB Plans Drift From Reality

The arithmetic is rarely the problem. These four input problems are, and each one is an integration problem rather than a buying problem.

The figures are not on the same basis

Point of sale reports are often GST inclusive and net of discounts. Ecommerce platforms may report gross sales before refunds. The ERP values stock at cost, the plan wants it at retail as well. Put these side by side without conversion and the plan is wrong by a margin that looks like a trading result. The feed has to convert every figure to one agreed basis, usually ex GST at both cost and retail, before it lands.

The periods do not line up

Many Australian retailers plan on a week based calendar such as 4-4-5 or 4-5-4, aligned to a July to June financial year, while the accounting system closes on calendar months. A sale on the last Sunday of a retail month can fall into the next calendar month. Unless every record is stamped with its retail week and period at source, last year comparisons and month end totals quietly disagree.

On order is dated by the wrong date

Purchase orders are usually stored against the date they were raised. For open to buy, what matters is when the stock will land and be available to sell, which for imported goods can be three to six months later and moves when a vessel is delayed. An on order figure bucketed by order date will consume the budget for the wrong period and leave buyers either frozen or overcommitted.

Reductions are invisible until it is too late

Markdowns, promotional discounts, staff discounts and shrinkage all reduce the retail value of stock and belong in the plan. In many stacks the only place they appear is buried inside a net sales number. If permanent markdowns are not captured separately at the time they happen, the plan cannot tell the difference between a range that sold through and a range that was cleared at half price.

What an Open to Buy Feed Has to Deliver

Six data sets, each with its own source system and its own way of going wrong. The plan template can be a spreadsheet or dedicated planning software. The feed is the same either way.

Weekly sales cube

Sales at cost and retail

Unit sales, retail value and cost of goods by SKU, store or channel, and retail week, drawn from every point of sale and ecommerce channel and converted to ex GST. Returns are netted by the period the return happened, not the period of the original sale, and marketplace orders are included with their own channel tag so they can be planned separately if needed.

Opening and closing stock

Stock snapshots

Stock on hand at the close of each retail week, by location, valued at both cost and current retail. Stock in transit between stores or from the warehouse is held as its own bucket so it is neither counted twice nor lost. The snapshot is taken at a fixed time so it agrees with the sales cut off, which is the detail that makes opening plus receipts minus sales equal closing.

Commitments by week

On order by landing period

Open purchase order lines from the ERP, bucketed by expected available to sell date rather than order date, with the expected date updated when the supplier or forwarder advises a change. Cancelled and partially received lines are reduced at the time of the change. For imported stock, the landed cost estimate carries through so the plan sees the real cost, not the supplier invoice price alone.

Markdowns and shrink

Reductions captured separately

Permanent markdowns recorded when the price changes, valued as the difference in retail across the stock on hand. Promotional discounts and staff discounts recorded from the transaction. Stocktake and cycle count write offs recorded as shrinkage. Each stays its own line so the planner can see why retail value disappeared, not just that it did.

Plan levels that match

Hierarchy and attributes

Department, class, subclass, season and brand mapped consistently across the ERP, the point of sale and the ecommerce platform, so a jacket is in Outerwear everywhere. Where systems disagree, one system owns the hierarchy and the others are corrected or mapped. Without this, a plan built at class level cannot be reconciled to actuals at class level.

Ready by Monday

Delivery to the plan

The finished data set delivered to wherever the plan lives: a shared spreadsheet refreshed in place, a reporting database, or the import format of a planning tool. A control total check runs before delivery, so if sales do not reconcile to the ledger within an agreed tolerance, the planner is told before the meeting rather than discovering it during one.

What Changes When the Feed Is Automated

Task	Traditional	Fed Automatically	Notes
Weekly OTB refresh	Exports pasted into a template	Refreshed overnight after week close	The planner spends Monday on decisions instead of on reconciling three exports.
A delayed container	Discovered when stock is late	On order moves to the new week	The landing date change flows through, so the budget for the affected period reopens or tightens automatically.
Mid season markdown	Hidden inside net sales	Recorded as a reduction	Planners can see how much of a period result was sell through and how much was clearance.
Last year comparison	Calendar months, misaligned	Same retail week, like for like	Requires a stored calendar table, including the 53rd week rule your business uses.
Online and store split	Separate reports, different bases	One cube with a channel tag	Useful if you plan channels separately, harmless if you do not.
New store opening	Plan built from guesses	Comparable store history to hand	Clean history by store makes the first plan for a new site less of a leap.
Buyer requests extra budget	Argued from instinct	Argued from current sell through	The conversation improves when both sides are looking at the same current numbers.
Sales do not match the ledger	Found at month end	Flagged before the plan is used	A control total against the general ledger catches missing stores and duplicate imports early.

Where Open to Buy Integrations Go Wrong

Building the feed before agreeing the basis

Decide in writing whether the plan is at cost, retail or both, ex GST or inclusive, gross or net of returns, and whether staff sales and marketplace fees are in or out. These are finance decisions, not technical ones, and changing them after the history has been loaded means rebuilding it.

Trusting PO dates

Supplier confirmed ship dates, forwarder estimates and actual receipt dates are three different things. Agree which date drives the on order bucket, keep the others for reference, and decide who updates the date when it slips. If nobody owns it, the on order figure becomes a historical document.

Hierarchy drift

New categories get created in the ecommerce platform for merchandising reasons and never mapped back to the planning hierarchy. Over a season, a growing share of sales lands in an unmapped bucket. The feed should report unmapped sales as an exception every week rather than dropping them into Other.

Stock values that move overnight

If retail value is calculated from the current price, a markdown taken on Tuesday changes last Sunday’s closing stock unless snapshots are frozen. Store the snapshot values at the time they are taken, and record the markdown as a reduction, otherwise opening plus purchases minus sales will never equal closing.

Over engineering a small business

If you have one store, one website and a single season a year, a well kept spreadsheet fed by two exports may be all you need, and many retail ERPs and inventory tools include an open to buy report that is good enough. Automate the feed when the weekly preparation is costing real hours or producing errors, not because the template looks old fashioned.

Treating the plan as private data

OTB data is commercial rather than personal, but sales feeds can carry customer identifiers if they are extracted at transaction level. Aggregate before delivery so the planning workbook holds no personal information, which keeps it outside the scope of most Privacy Act 1988 and Australian Privacy Principles obligations and lets it be shared more freely.

How Yes AI Approaches Planning Data

Basis and calendar agreed first

We start with your planner and your finance lead and write down the basis, the calendar and the hierarchy, including how returns, transfers and the 53rd week are treated. That document is the specification and it stays yours.

History loaded and reconciled

Two or more years of sales, stock and receipts loaded on the agreed basis and checked against the ledger by period, so last year comparisons are real from the first plan rather than built up over time.

Feeds run and monitored by us

The extracts run on a managed cloud automation layer we operate, with control totals, exception reports for unmapped products and missing stores, and an alert if the weekly refresh does not complete.

Honest about tool choice

If your ERP or planning tool already has an open to buy module that fits, we will say so and feed it rather than build around it. If a spreadsheet is the right home for the plan, we keep it in the spreadsheet.

From Monday Exports to a Plan That Refreshes Itself

Five steps. Most retailers have a working weekly refresh within five to eight weeks, with history loading as the usual long pole.

Document the plan as it really works

The template, the formula, the hierarchy, the calendar and the sources for every input, including the manual adjustments the planner makes each week and why.

Agree basis, calendar and ownership

Ex GST at cost and retail, retail weeks and periods, one owner for the merchandise hierarchy and one owner for landing dates on purchase orders.

Build extracts and load history

Sales, stock snapshots, on order, receipts, reductions and transfers extracted on the agreed basis, with two years of history loaded and reconciled to the ledger.

Run in parallel for a month

The automated feed runs alongside the manual process for four weeks. Differences are investigated to root cause until the planner trusts the automated numbers more than their own.

Switch over and extend

Manual preparation stops. Later additions often include store level allocation data, supplier performance on landing dates and size curve analysis for apparel.

FAQ

What is open to buy in retail?

Open to buy is the amount of stock a retailer can still purchase for a period without exceeding its inventory plan. A common form of the calculation is planned sales, plus planned reductions such as markdowns and shrinkage, plus planned closing stock, minus opening stock. That gives the planned purchases for the period. Subtract what is already on order for the period and the remainder is open to buy. It is usually expressed at retail value, at cost, or both.

Should open to buy be calculated at cost or retail?

Both, if you can. Retail value connects the plan to sales and markdowns, which is how buyers think. Cost value connects it to cash and the balance sheet, which is how finance thinks. The integration can deliver both from the same records as long as cost and current retail are captured for every SKU at every snapshot. Whatever you choose, apply it consistently and exclude GST so the figures match the ledger.

Can we keep using our open to buy spreadsheet?

Yes, and many retailers should. The spreadsheet is rarely the weak point. The weak point is the manual exports and pasting that feed it. Automating the inputs and refreshing the workbook in place keeps the tool your planners know while removing the hours and the errors. Dedicated planning software makes sense once you plan many stores, channels or seasons at a granular level, and it needs exactly the same feed.

How should on order be dated in an OTB plan?

By the date the stock is expected to be available to sell, not the date the purchase order was raised. For imported goods that can be months apart, and it moves when shipments are delayed. The integration should take the best available landing estimate from your ERP or forwarder updates and re bucket the order when it changes, so the budget for each period reflects what will actually arrive in it.

How do we handle a 53 week year?

Week based retail calendars accumulate a spare day each year, plus another in leap years, so every five or six years one year has 53 weeks. Businesses handle the extra week differently: some add it to the last period, some exclude it from comparisons, some restate last year. The important thing is that the rule is decided once and stored in a calendar table the feed uses, so every report treats the week the same way.

Does our ERP already do open to buy?

Some retail ERPs and inventory systems include an open to buy or merchandise planning module, and some planning tools connect directly to common platforms. If yours does and it covers your hierarchy, calendar and channels, use it. Integration work is still often needed to bring in channels the ERP does not see directly, such as a separate ecommerce platform, a marketplace or concession sales, and to correct the on order dates.

How long does an open to buy integration take?

A first automated weekly refresh is typically live in five to eight weeks. The time goes into agreeing the basis and calendar, mapping the merchandise hierarchy across systems, and loading and reconciling history. Running the automated feed in parallel with the manual one for about a month before switching over is time well spent, because trust in the numbers is the whole point.

Make Your Buying Plan Run on Current Numbers

Book a call. We look at how your plan is fed today, show where the figures diverge, and give you a priced plan to automate the feed. The findings are yours whether or not we do the work.

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All discussions held in confidence. Australian-based consultants.