Our team
Where supply-chain strategy meets deep SAP aATP implementation expertise.
SizeGrid is a focused SAP consulting team for companies dealing with constrained supply, advanced ATP, complex order fulfilment and S/4HANA logistics transformation. We combine named senior consultants with a small circle of specialist contributors for development and SAP platform topics.

Founder and SAP aATP solution architect
Andriy Ripka
SAP architect focused on advanced ATP, SAP S/4HANA logistics, Retail, Fashion, CAR and custom SAP process extensions.
Focus: turning complex promise logic into executable SAP architecture.
LinkedInAndriy has worked across many SAP logistics, retail and fashion projects, from SAP AFS and IS Retail to FMS, CAR and S/4HANA advanced ATP. His project background includes participation in SAP-led product and customer initiatives, including the large AFS-to-FMS transition program with major fashion customers and later validation of future S/4HANA capabilities in the ATP area. This gave him a practical view of how business requirements, standard product capability and future process architecture are shaped together – and where expert design is needed to turn standard functionality into a working supply-chain process.
This path shaped the SizeGrid idea. In supply chain there are niche processes where deep knowledge really matters: constrained supply distribution, product allocation, supply assignment, segmentation, e-commerce availability and controlled delivery release. In these areas, it is often not enough to read the SAP manual. The right solution requires process experience, technical realism and sometimes a carefully designed add-on that extends the power of standard SAP without replacing it.
At SizeGrid, Andriy leads the design of advanced ATP concepts, fair distribution mechanisms, prepacking concepts and SAP extensions for customers who need to solve scenarios that are too specific, too interconnected or too business-critical for a generic template approach.
- Full responsibility for advanced ATP concepts and implementation in complex S/4HANA projects.
- Long-term background in retail, fashion, sports and omnichannel scenarios where availability is a core business decision.
- Focus on practical add-ons that strengthen standard SAP for constrained supply, allocation and distribution scenarios.

Senior SAP business consultant
Naushina Nayeem
SAP SD techno-functional consultant with deep OTC, DTC, CRM, integration and advanced ATP experience.
Focus: making ATP-relevant order fulfilment work end to end.
LinkedInNaushina brings more than 16 years of SAP SD and order-to-cash experience, with a strong focus on advanced ATP and the surrounding fulfilment processes. She has also worked as a solution architect, which gives her a broad view of the processes around ATP: order capture, CRM and DTC flows, intercompany setup, STOs, returns, external integrations and operational fulfilment.
At SizeGrid she works on aATP-related functions such as Product Allocation, Supply Protection, ARUN, ATP change log, order fulfilment optimization with SAP standard BAdI enhancements, product substitution with ATP checks and prepacking setup using size curves. Her hands-on ABAP background helps translate complex requirements into elegant, minimum-effort solutions and makes it possible to prototype ATP-surrounding processes from scratch, demonstrate realistic scenarios and quickly validate design options with business stakeholders.
- Combines functional SD knowledge with technical understanding of BAdIs, APIs, IDocs, OData and integration patterns.
- Experience as DTC and CRM architect, OTC stream lead and senior SAP SD consultant across international rollouts.
- Strong fit for projects where ATP rules must be reflected in customer service, order processing and external channels.
Specialist contributors
Additional senior expertise behind the public team.
In addition to the public profiles above, SizeGrid is supported by senior specialists who strengthen development, system platform and technical validation. This gives the team the ability to move from concept to prototype, from prototype to add-on design, and from design to a realistic SAP demonstration environment.
Specialist roles shown transparentlySAP aATP senior ABAP developer
Senior SAP developer with more than 20 years of experience in ABAP and SAP enhancement technologies. He supports advanced ATP extensions, BAdIs, performance-sensitive logic, integration points and SizeGrid add-ons where the standard process needs a precise and maintainable extension.
SAP Basis and platform consultant
SAP Basis consultant responsible for SizeGrid’s internal SAP environment, including the latest S/4HANA landscape as well as AFS and CAR systems used for prototyping, analysis, demonstrations and realistic validation of logistics and ATP concepts.
Shared capability
Where the team creates the most value.
The strongest SizeGrid contribution is not one isolated module. It is the connection between aATP, SD/OTC, logistics execution, planning input, customer channels and custom SAP extensions.
ATP architecture
Design end-to-end promise logic with PAL, SuP, ARUN, segmentation, RLT, substitution and prioritization rules.
Order fulfilment
Translate ATP decisions into sales order handling, customer service visibility, delivery release, STO and intercompany processes.
Integration
Connect S/4HANA with e-commerce, CRM, planning tools, 3PL WMS, APIs, EDI, SAP CPI and availability snapshot processes.
Extensions
Build controlled add-ons where standard SAP provides the foundation but business rules need a more precise mechanism.
Practical project background
Experience from retail, fashion, sports, e-commerce and international OTC programs.
SizeGrid experience is rooted in industries where availability is not simple: seasonal goods, size grids, constrained production, market allocation, omnichannel promise, store and wholesale distribution, and customer-specific fulfilment rules.
Functional depth
We understand the business question behind the transaction: who should receive constrained supply, when the promise should become firm, and what should happen when priorities change.
Technical realism
The team can discuss standard SAP configuration, BAdIs, integration constraints and performance-sensitive availability processes without separating concept from implementation.
Focused boutique model
Customers work with a small team specialized in ATP and fulfilment, supported by trusted contributors for development and SAP platform topics.
Need a second opinion on an ATP decision?
We can review a specific aATP design, prototype an alternative, or help define the logistics direction before the implementation project starts building.
