Diagram illustrating Tier 1 modular production integrated with SAP cloud and manufacturing systems.
Modular production is a manufacturing approach in which parts and functions are designed and produced as modules, then combined at final assembly to achieve high product variety, short lead times, and strong production efficiency.
For Tier 1 automotive suppliers, this is no longer just a production concept. It is a business model, a supply chain design principle, and a systems architecture challenge that spans engineering, procurement, quality, logistics, and manufacturing execution.
This article explains the definition, background, and purpose of modular production, then shows how Tier 1 suppliers can apply it in practice. It also outlines how to model modular production in SAP S/4HANA Private Cloud and SAP Digital Manufacturing, including a hybrid setup with existing MES platforms.
Modular production is a manufacturing method in which a product is divided into functional units, or modules, and each module is designed, procured, produced, and quality-checked separately before being combined in the final process to complete the product.
In the automotive industry, typical examples include front-end modules, cockpit modules, seat modules, and suspension modules. These are not just grouped parts; they are production and responsibility units that help standardize work while still supporting OEM-specific variation.
The main background for modular production is the rise of high-mix, low-volume manufacturing and shorter product cycles. As vehicle models and specifications multiply globally, suppliers need a more efficient way to expand derivative models using common modules plus differentiated parts.
Another key driver is the shift of module development responsibility from OEMs to Tier 1 suppliers. In many cases, the OEM transfers development, quality, and cost responsibility by functional area to the supplier, making the Tier 1 act as a module integrator.
The purpose of modular production is threefold: improve standardization and reuse, shorten lead times and improve production efficiency, and strengthen quality and traceability.
For Tier 1 suppliers, a module usually means a common core function plus an OEM-specific customization layer. This allows one platform to serve multiple OEMs and multiple vehicle programs while keeping the stable core standardized.
From a management perspective, the Tier 1 must act as a module supplier that guarantees performance, quality, and cost at the module level. In some cases, this also includes managing sourcing from lower-tier suppliers as part of an integrated responsibility model.
From production planning and manufacturing control viewpoints, modular production changes several key areas.
Here are three common examples of modular production in Tier 1 automotive manufacturing.
A cockpit module may include the instrument cluster, infotainment unit, air vents, wiring harness, and airbags as one integrated supply unit. The modular approach is to standardize the internal frame, brackets, and selected electronic units while allowing OEM-specific design and switch layouts.
In production, internal units are assembled on a sub-line, function-tested, and labeled with a barcode or serial identifier. Then the final line adds trim, surface materials, and OEM-specific parts.
A seat module typically includes the seat frame, cushion, cover, seat rail, airbags, and seat heater. The modular strategy is to standardize the structural base, such as the frame and rail, while differentiating through upholstery, cushion specifications, and optional functions.
In production, the seat frame module is built on a common line. Final upholstery and end inspection are performed on separate lines depending on model and grade.
A suspension or corner module may include the shock absorber, spring, arms, bearings, and brake-related units supplied as one integrated module. The objective is to deliver a complete suspension unit in time to help reduce takt pressure on the OEM body assembly line.
In production, the corner module line performs integrated assembly, adjustment, and function testing, while maintaining lot-level or VIN-level traceability for later use and quality control.
The success of modular production depends on three areas: business process design, organizational governance, and systems design.
On the business and organization side, the company needs a clear definition of module ownership. The scope of responsibility should cover sales, engineering, production, procurement, and quality, and it should be agreed with both internal stakeholders and OEMs.
Standardization governance is also critical. If OEM-specific exceptions are allowed too easily, the module standard breaks apart and the company ends up with the same complexity as traditional part-based management. The allowable range of derivative variants must be defined in advance and enforced in project and sales reviews.
On the manufacturing and logistics side, the company must decide how to split responsibility between plants and sites, where to perform sub-assembly, and what to outsource to Tier 2 suppliers. Inter-module supply scenarios should also be considered, because a company that supplies one module may also become a supplier of another module.
On the systems and data side, the company must design module BOMs, routings, traceability structures, and cross-system integration between ERP, MES, and PLM. The data model must support future design changes without becoming too large or too rigid.
In SAP S/4HANA Private Cloud, modular production is usually modeled through a layered combination of material master data, BOMs, routings, and production versions.
The basic data model includes:
For BOM design:
For routings and production versions:
A good design separates platform-common modules from OEM-specific modules at the material and BOM level. Production versions can then be used to switch between different lines for the same module, such as a standard line, a high-efficiency line, or a local factory line.
In planning, MRP and PP/DS should explode modules as true intermediate products so that common module pre-production and final assembly orders can be offset in time. This allows preparation inventory to exist where it adds value, without losing control of timing.
SAP Digital Manufacturing is SAP’s cloud MES and MOM platform, and it integrates natively with SAP S/4HANA. It connects ERP, shop floor equipment, and operators in near real time.
Its main functional areas include:
In a modular production scenario, SAP S/4HANA can release module-level production orders to SAP Digital Manufacturing. The DM layer then provides assembly instructions for the module build and sends work guidance to operators and equipment.
When a module is completed, it can be assigned a serial number or module ID and linked to the serial or batch numbers of its components for traceability. At the final assembly line, the required module IDs are scanned and consumed, and the relationship between the finished product and its installed modules is recorded as part of the manufacturing history.
This is especially valuable for quality analysis and recall containment. It also enables line-level analysis of OEE, defects, and downtime causes so that bottlenecks can be improved with evidence rather than assumptions.
In many Tier 1 plants, an existing local MES or custom-built system is already in use. In that case, a full replacement by SAP Digital Manufacturing may not be the best first step. A coexistence or hybrid model is often more realistic.
Typical patterns include:
The main design issues are master data ownership, traceability scope, integration granularity, and security architecture for cloud and on-premise coexistence. In practice, the system of record for materials, BOMs, and routings is often kept in SAP S/4HANA, while execution systems consume that information through controlled interfaces.
A practical rollout can be organized in stages.
For Tier 1 automotive suppliers, modular production is a strategic way to standardize what should be common, customize what must remain different, and manage manufacturing execution with far better traceability.
The first step is to decide which functional area the company wants to compete in as a module integrator. After that, the target product families should be decomposed from a module perspective, and the scope of standardization, production control, quality control, and traceability should be agreed across business, system, and organization design.
If SAP S/4HANA PP and SAP Digital Manufacturing are clearly separated by role, and module BOMs, routings, execution data, and traceability are connected end to end, implementation becomes much more stable and scalable.
Parts of this article were developed with reference to generative AI suggestions and were reviewed, refined, and supplemented based on the author’s professional expertise and judgment.
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