Protected supply vs. isolated supply

Every business wants to set goods aside – and wants it with as little extra effort as possible. So the real design question is: how strict must the separation be, and how much process complexity is acceptable to get it? Stock and demand segmentation changed that trade‑off: real isolation, without new master data or organizational objects. And it is a decision to make early.

Every supply chain sets goods aside: for a key account, a channel, a quality grade, a country of origin. And every company wants the same two things at once – separation that is strict enough, and as little extra effort as possible.

Those two wishes fight each other. Strictness was traditionally bought with structure: extra material codes, extra storage locations, sometimes an extra plant. Flexibility came cheap – a protected share inside one pool – but it leaked where leaking was not allowed.

For a long time there was no real middle. This article is about the S/4HANA capability that created one – and about the pains it removes.

If any of these situations sound familiar, this article is for you:

• A key account opens a parcel and finds B‑goods. Claim, return freight, and a credibility dent that outlasts the credit note.
• A shipment with the wrong country of origin reaches a border. In today’s tariff environment, origin can decide between zero duty and a punitive rate – and a wrong declaration adds penalties and blocked goods on top.
• Master data grows a twin article for every quality grade or carton variant. Purchasing, planning, pricing and reporting all split with it.
• Stock is “protected” by spreadsheets and locked storage locations – and by the discipline of whoever is on shift today.

The half of the problem that gets all the attention

Almost every ATP requirement we see contains the same sentence: “these goods need to be held for…” A key account. A market. A channel. Getting this right is genuinely hard – how much to hold back, for whom, for how long, and what happens to the reserve when the season ends.

The good news: this half of the problem is well served. S/4HANA’s advanced ATP brought serious tools for it. Product Allocation caps consumption by market or customer group. Supply Protection – a newer tool that deserves the attention it gets – holds back defined quantities of a shared pool for the groups that matter. Much has been written about both.

Both answer one question: how much of the common pool may each group consume?

But a second question hides behind the first, and it gets written about far less: what if certain goods should not be in the common pool at all?

Some goods need a wall, not a fence

Take the classic fashion case: quality grades. Part of your stock is B‑grade – slight flaws, customer returns, end‑of‑season regrading. Commercially it is a different product. But a second material code would double the master data, so it lives under the same material as the A‑goods.

What should the availability check do with it?

For a normal order, B‑grade stock should simply not exist. Never confirmed, never proposed, never quietly filling a shortage. Only when a customer explicitly buys B‑goods – an outlet, a specialised reseller – should exactly this stock become visible. And then only this stock.

That is not “hold back a share.” That is isolation. Reservation tools manage shares of one pool. Here, the pool itself has to be split – and each order only ever sees the compartment its rules allow.

The stock overview may show 1,200 pieces. For a standard order, the only true answer is 800 – because the 400 B‑grade pieces are not “later.” They are “never.”

The workarounds every warehouse knows

Because the requirement is old and the tooling used to be limited, companies learned to express this rule through physical logistics objects.

Separate material codes for the “special” goods. One product becomes two SKUs. Purchasing, planning, reporting and history split with it.

Separate storage locations – the classic for quality stock. B‑goods live in their own storage location that normal orders shouldn’t touch. It works, until the characteristics multiply. A company sourcing from ten or more countries does not want a storage location per country, with the warehouse structure dictated by a sales rule.

Batch data – the origin of goods is often recorded on the batch. True, but an attribute is not a rule. The batch knows where the goods were made. It does not know which orders may consume them. And with tariff regimes and preferential‑origin agreements shifting the way they have recently, “where was it made” has become a commercial question that belongs in the order confirmation – not a note discovered at picking.

All of these approaches do the same job – they set supply aside for a purpose. What separates them is how hard the separation is. At one end: a protected share of one common pool, as with Supply Protection. At the other: a fully separate material, storage location or plant – complete separation, paid for in master data and organizational complexity. What was missing for a long time is the middle: real isolation, without the structural price. That is exactly where stock and demand segmentation sits.

A label on supply, a label on demand – and rules between them

Stock and demand segmentation, in business terms: every piece of supply carries a stock segment. Every demand carries a requirement segment. A rule set defines which demand may consume which supply.

No extra plants. No extra storage locations. No duplicated material masters. The walls are logical, and the availability check respects them natively. Three properties make this more than a technical convenience.

1. The rules live in the system, not in people’s discipline. A storage location can be entered on a purchase order or a sales order too – but keeping the wrong orders away from the wrong storage location depends on user discipline, training and custom checks. A segment is determined automatically, and the consumption rules are enforced by the availability check itself.

2. One segment can combine several characteristics. A pool of stock can be, at the same time, reserved for retail, quality A and made in Portugal. The combinations follow your business, not your org structure.

3. Walls can have doors. Isolation does not mean rigidity. The rules define fallback sequences: a standard order may consume Chinese A‑goods first, then Portuguese A‑goods – and never B‑grade. Today these rules follow the ATP pool concept, strictly one‑to‑many: one demand type consumes an ordered pool of stock segments – and each stock segment can belong to only one pool, one rule.

One more design decision belongs on the table from day one: how physical should each wall be? Some segments should follow the goods into the warehouse – B‑goods usually should, so pickers cannot grab them for A‑orders. Others are purely commercial and should stay a sales‑side rule, invisible to warehouse operations. This is a judgement call per characteristic – and one of the reasons segmentation is an architecture topic, not a configuration detail.

Not one or the other

Two clarifications before this sounds like a tool contest.

Walls can reserve, too. Give a segment a characteristic equal to the distribution channel, and stock procured for retail feeds retail demand only. That is reservation – just the strict form of it. The goods are earmarked from the purchase order onward, and other channels never see them. Where leakage between channels must be zero, the wall is the better reserve than any fence.

And the tools stack. Segmentation and Supply Protection are not competitors. Draw the walls with segments – channel, quality, origin – and let Supply Protection manage the flexible shares inside a segment: for example, protecting quantities for key accounts within the wholesale segment. One layer defines what the pool is; the other manages who gets how much of it.

The choice is a design question, not a product question: which lines must never be crossed, and which are shares that may flex under pressure?

The quiet bonuses

Segmentation is anchored deep in the material master. That has a pleasant side effect: the same segment key unlocks a whole set of standard features – without a second material code.

The barcode that routes itself. Different stock segments of one material can carry different EAN codes. When an order line arrives with the EAN that belongs to Portuguese‑origin goods, the order gets the matching requirement segment automatically. The availability answer then comes only from Portuguese‑origin supply – even if other stock sits free. For EDI‑heavy wholesale intake: no user decision, no custom code.

Finance sees the same split. Segments can carry their own valuation: B‑grade stock valued at B‑grade prices, while sharing the material master with the A‑goods. ATP and accounting use one classification of supply instead of two parallel truths – and the inventory on the balance sheet reflects what the goods can actually be sold for. In our projects, this is often the argument that wins finance over.

And the list goes on. All of these can differ per segment of the same material:

And the label travels. Segmentation is not a sales‑side trick. Planning understands it, warehouse processing supports it, and Supply Assignment (ARun) respects it when pinning supply to demand. If “Confirmed” is not “reserved” was about firmly linking specific supply to specific demand, segmentation defines something even more fundamental: which supply a given demand may be linked to at all. It is no coincidence that on our interactive ATP process map, segmentation is one of the few elements drawn vertically – crossing every layer from planning down to delivery execution.

Where we take it further

Once you stop treating segmentation as a quality‑stock feature and start treating it as a design layer, uses appear that have nothing to do with quality or origin. Two examples from our own practice:

Prepacks without prepack articles. Classical SAP Retail requires a separate article for every carton composition – a master‑data burden heavy enough that many companies avoid prepacking altogether, despite the clear logistics benefit. We use segments instead: prepacked cartons and loose goods are separated inside the same material, customers keep ordering normal single SKUs, and the twin‑article footprint disappears. The approach is described on our segmentation‑based prepacking page.

Procurement that remembers its purpose. When goods are procured for a specific customer, order or market, that purpose is usually lost the moment they arrive as anonymous stock. Carried as a segment, the purpose survives goods receipt, stock transfers and warehouse moves – so earmarked supply stays earmarked through a long supply chain, and exceptions (a reduced order, a late arrival, a more urgent demand) can be handled by rule instead of by hunting through spreadsheets.

The pattern is always the same: wherever a physical workaround – an extra article, an extra storage location – exists only to encode a business rule, a segment can usually replace it. The tool doesn’t change; the walls are simply drawn where your business needs them.

Decide early – this one reshapes master data

Formally, segmentation belongs to ATP. In practice it touches material master design, stock posting, warehouse processes, prices, valuation and planning. That is its strength – and the reason it must be decided at blueprint stage.

Retrofitting segments under a live material master and converted stock is hard, and sometimes practically impossible. The way materials, stocks and open documents were migrated has already baked in the answer.

For companies designing their S/4HANA transformation now, the question costs one workshop: which of our supply must be separated – not just reserved? Quality grades. Origins. Channels. Prepacked goods. Even if the answer today is “none,” you will have made that decision consciously – with the master data still on the drawing board.

Where does your company sit today: soft shares, heavy structure, or already something in between? Join the discussion on LinkedIn or get in touch.