ATP is supply-chain architecture.

Planning and ATP are deeply connected.
Planning provides the availability picture: future supply, product-group availability, market reservations, customer priorities, and other constraints. ATP translates this input into concrete promise decisions.

But the influence also works the other way around. Advanced ATP capabilities can unlock planning scenarios that were difficult or impossible in a legacy ERP setup — for example flexible source determination, allocation logic, or controlled use of constrained supply.

One of the major advantages of advanced ATP is Product Allocation - PAL. It allows ATP to work naturally on the same level as planning, instead of being limited only to detailed stock availability on SKU level.

In many businesses, supply constraints are not always known at the exact material, size, color, or location level from the beginning. They may exist on a higher planning level: product group, collection, market, customer group, capacity bucket, textile group, component availability, or production capacity. PAL makes it possible to translate this high-level planning information into ATP-relevant availability limits.

These constraints can be calculated in external planning applications or in SAP planning tools, and then communicated to S/4HANA. Once available in S/4HANA, they can influence order confirmation, reservation logic, prioritization, and supply distribution.

SizeGrid has strong experience in designing and building such integrations - both with external planning solutions and with SAP tools such as CAR. This makes it possible to connect planning decisions with operational ATP execution and create a more controlled, business-driven confirmation process.

External planning may define supply on an aggregated level, such as product group, collection, market, or capacity bucket. Production planning then needs to translate this into specific SKUs, plants, dates, and quantities so that MRP and manufacturing processes can run.

This detailed availability picture can differ from the original high-level plan because of capacity changes, component shortages, production sequencing, or plant-specific restrictions.

SizeGrid has experience in modelling these processes, integrating external planning input into production, and broadcasting committed SKU-level availability back to local markets and ATP processes - including complex hybrid landscapes where some production plants remain in legacy systems during transformation.

Aggregated availability combines planned and committed supply into one market-relevant view.

This can be difficult because planning and production often work on different levels. Planning may provide availability by product group, collection, or market, while production creates committed availability by SKU, plant, date, and quantity.

One of the biggest risks is double counting. The planning system may not know which planned supply has already been converted into detailed production commitments. As a result, the same supply can appear both as high-level planned availability and as committed SKU availability.

SizeGrid helps define the logic for combining these availability sources correctly, so that markets receive a consistent and reliable picture for allocation, distribution, and ATP confirmation

Fair cross-market distribution is a SizeGrid custom solution for controlled supply allocation across markets.

When supply is limited, standard ATP processes may confirm orders mainly based on timing: the market that enters orders first can consume a disproportionate share of available stock. This is not always aligned with business priorities.

The SizeGrid ARUN based add-on helps distribute constrained supply more fairly. It can compare demand across markets, apply fair-share rules, protect supply for selected regions, and support transparent redistribution based on business criteria such as forecast, allocation share, market priority, or strategic demand.

This allows companies to move from simple stock consumption to a more controlled, business-driven confirmation process.

ATP availability is not static. It can change every second.

External systems need reliable and up to date availability information, but this is often more complex than a simple stock export. Availability may depend on customer group, sales channel, market, product segment, allocation logic, supply protection, or other ATP rules.

For companies with a large assortment and complex ATP scenarios, creating such snapshots can be technically and functionally challenging.

SizeGrid has experience in combining SAP standard mass ATP calculation mechanisms with custom logic to generate fast, reliable, and business-relevant availability snapshots for external use. These solutions are proven in productive operation across multiple companies.

Multi-level ATP combines committed SKU-level supply with higher-level planned availability.

A common approach is to use standard ATP for the near-term horizon and RLT together with Product Allocation for the more distant horizon. This can work well, especially with the advanced RLT calculation mechanisms in aATP.

But in complex business scenarios, the border between these horizons is not always clear. Orders requested after RLT may still need to consume available or committed supply. At the same time, earlier orders may need access to high-level planned availability when detailed SKU commitments are not yet fully available.

SizeGrid has experience in designing such mixed ATP scenarios by combining SAP standard tools with custom logic. This helps companies create flexible confirmation processes across different planning levels, time horizons, and availability sources.

In complex ATP scenarios, companies sometimes need to give customer service teams more flexibility to manage order confirmations. Customer service may need to fine tune confirmed quantities, react to urgent business situations, or move supply from one order to another when priorities change.

This flexibility can be very valuable, but it also creates risks. In a central distribution model, different markets may compete for the same limited supply. One typical challenge is the use of old high-priority orders to capture supply, which is later swapped to newer orders. These so-called “golden orders” can be reused multiple times and may distort the intended distribution logic.

SAP advanced ATP provides functionality such as extended FIFO to control some of these situations. It can help ensure that supply is not freely reassigned in a way that violates chronological or priority-based rules. However, in many real-life scenarios, standard FIFO logic is not enough.

The situation becomes even more complex when supply swaps are performed through ARUN or Supply Assignment mechanisms. These processes may influence confirmations in ways that are not fully covered by standard FIFO control. As a result, companies may need more precise rules to define when supply can be moved, which orders are protected, and which priority changes are allowed.

SizeGrid has experience in designing and implementing advanced prioritization controls for such scenarios. This includes combining SAP standard aATP functionality with custom logic to prevent unwanted supply manipulation, protect fair distribution principles, and still preserve the operational flexibility that customer service teams need.

Stock and demand segmentation is a powerful capability that is still underestimated outside the fashion world. In earlier AFS scenarios, similar business concepts were known through stock categories. With S/4HANA, this logic becomes relevant for many other industries that need more precise control over how supply is reserved, protected, and consumed.

The key idea is that supply and demand can be separated not only by classic logistics objects such as plant, storage location, or batch. Segmentation adds an additional layer on top of physical and also expected stock. This layer can be based on characteristics such as quality, country of origin, production source, market destination, customer relevance or other business-specific attributes.

As a result, companies can define rules that determine which demand is allowed to consume which segment of supply. The same product may physically exist in stock, but it may only be available for certain markets, channels, customer groups, quality requirements, or logistics scenarios.

At SizeGrid, we use stock and demand segmentation extensively and often in creative ways. For example, we developed a factory prepacking solution based on the segmentation framework, where segmentation characteristics help control how goods are prepared, assigned, and distributed before they reach the final market.

This makes segmentation much more than a technical classification of stock. It becomes a flexible design tool for advanced ATP scenarios, controlled supply reservation, market-specific distribution, prepacking logic, and complex S/4HANA transformation processes.

Procure-to-order is a classical SAP process that allows companies to trigger procurement based on specific customer demand. It is also integrated with advanced ATP, which makes it relevant for scenarios where sales order confirmation and procurement execution must stay closely connected.

However, standard PTO logic may not be flexible enough for all business models. One important limitation appears in retail scenarios where stores are supplied through stock transfer orders. If procurement needs to be targeted not only for a sales order, but also for STO-based store replenishment, the standard approach can become difficult to apply.

Another challenge is exception handling in long and complex supply chains. Goods may be ordered from a vendor for a specific customer, but later the customer may reduce the requested quantity. A more urgent or higher-priority demand may appear. Supply may arrive late, partially, or in a different structure than expected. In these situations, companies need a controlled way to release, redirect, or reassign procured supply without losing transparency.

At SizeGrid, we have developed solutions for such flexible PTO scenarios. Our approach helps companies extend the classical procure-to-order concept and make it more suitable for complex retail, wholesale, and intercompany processes.

We also offer an additional PTO concept based on the stock and demand segmentation framework. This allows companies to separate procured supply by business characteristics and define more precise rules for how this supply can be consumed, reassigned, or protected. As a result, PTO becomes not only a procurement trigger, but a flexible mechanism for controlled supply reservation across complex logistics networks.

Prepacking is a classical logistics process where a factory or vendor creates identical cartons with a predefined mix of different SKUs. In fashion, this may be a set of different sizes of the same style. In food or consumer goods, it may be a carton containing different flavors, variants, or product types.

The classical SAP Retail approach supports prepack scenarios, but usually requires a separate article for each prepack structure. This means that every carton composition becomes a separate object that must be integrated, planned, ordered, received, distributed, and monitored. For many companies, this creates an unacceptable level of complexity in master data, integration, planning, and daily operations.

As a result, companies often avoid using prepacking even when the business benefit is clear. The process can be highly efficient for factory packing, store replenishment, wholesale distribution, and seasonal logistics, but the operational cost of the classical setup may be too high.

At SizeGrid, we have been developing a leaner alternative for many years. Our approach uses the stock and demand segmentation framework to represent preferred packing logic without forcing companies to create and maintain separate virtual prepack articles for every carton structure.

This makes the process much more flexible. Customers can continue ordering normal single SKUs and specify the preferred packing logic where needed. The system can then use segmentation-based rules to support factory or vendor prepacking, supply assignment, distribution, and ATP-related control.

The concept is no longer limited to classical retail scenarios. It can also be used in wholesale, intercompany, and complex supply chain models where companies want the efficiency of prepacks without the heavy operational footprint of traditional prepack article management.

E-commerce orders are often technically created as normal sales orders, but the business expectations behind them can be very different. Online customers usually expect an immediate and reliable confirmation. If the product is shown as available, the company should be able to deliver it quickly and without later corrections.

For this reason, eCom orders may need a specific ATP strategy. In some scenarios, eCom demand should only consume currently available physical stock. If there is no stock available now and only future supply exists, the order should be rejected or handled through a separate process. This helps avoid unrealistic promises and protects the customer experience.

In other scenarios, companies may allow more flexibility. Before rejecting an eCom order, the system may try to reprioritize supply. For example, it may be acceptable to move confirmation away from earlier but lower-priority demand in order to fulfill a newer eCom order with higher business importance. This can be relevant when eCom represents a strategic channel, direct customer commitment, or a higher-margin sales model.

The challenge is to control this flexibility carefully. Companies need clear rules defining when eCom orders can access only current stock, when they can consume future supply, and when they are allowed to trigger reprioritization against other demand.

At SizeGrid, we face such scenarios very often. We have developed best practices for modelling eCom ATP processes using standard aATP tools. This includes designing confirmation strategies, prioritization logic, supply protection, product allocation, and controlled reprioritization scenarios so that eCom orders can be processed quickly, reliably, and in line with business priorities.

ARUN, or Supply Assignment, is one of the most powerful ATP-related tools that is still not widely known outside the fashion industry. Although its origins are strongly connected with SAP AFS and fashion processes, S/4HANA makes this type of functionality relevant for many industries that need precise control over how supply is consumed by demand.

The main value of ARUN is that it allows companies to go beyond a simple ATP check. Instead of only calculating whether supply is available, the system can create a controlled assignment between specific demand and specific supply. For example, a sales order item or stock transfer order item can be linked to a specific future purchase order item. This assignment can persist for months and can reserve only part of the purchase order quantity, not necessarily the full item.

This opens many advanced logistics scenarios. Companies can protect future supply for selected customers, markets, channels, or orders. They can control redistribution of constrained products, manage exceptions in long supply chains, and fine tune which demand should receive which supply at a very detailed level.

At SizeGrid, we have worked with ARUN and Supply Assignment for more than a decade, starting from its origins in the SAP Apparel and Footwear Solution. This long experience allows us to use the tool not only in classical fashion scenarios, but also in more creative and industry-independent logistics processes.

We have also developed our own custom ARUN-based mechanism for fair distribution of supply between flexibly defined demand groups, such as markets, customer groups, channels, or other business segments. This helps companies distribute limited supply in a controlled and transparent way, instead of relying only on order entry sequence or manual intervention.

Delivery creation looks like one of the simplest and most established SAP processes. It has existed for decades and is often treated as a purely operational step after order confirmation. However, in complex supply chains, the question is not only whether a delivery can be created. The real question is how much should be released for delivery, when, and under which business rules.

Many companies need much more granular control over this process. For example, customer service may need to see how much supply is currently reserved for an order and then decide exactly how many pieces should be delivered now. In other cases, customers may allow partial deliveries, but only if meaningful parts of the order can be fulfilled. A business rule may require that all sizes of a style are delivered together, or that a complete order can only be partially delivered if at least 70% of the quantity is available.

These requirements can be difficult to manage with simple delivery creation logic. They require a controlled step between order confirmation and delivery execution, where the business can evaluate what is ready, what should wait, and what can be released without damaging the customer experience.

SAP provides standard functionality for this type of scenario through Release for Delivery, a process that also has strong roots in fashion and seasonal distribution. It allows companies to control which confirmed quantities are actually released to delivery creation based on predefined rules and business decisions.

At SizeGrid, we use Release for Delivery extensively in advanced ATP and distribution scenarios. It helps our customers improve communication with their own customers, reduce manual coordination, and simplify operational processes. Instead of creating deliveries too early, too late, or in commercially unsuitable quantities, companies can release supply in a more transparent and business-driven way.