What types of constraints can APS handle?

A real-world production system is subject to countless constraints that directly impact production planning and sequencing. When we talk about APS systems (Advanced Planning and Scheduling), especially those focused on detailed sequencing, considering these constraints is essential for generating viable and efficient plans.

The Opcenter APS, Siemens' sequencing software, allows for the construction of models that handle a wide range of constraints, such as:

• Material Constraints

• Routing and Valid Resource Constraints

• Secondary Constraints

• Advanced Resource Constraints

• Parent-Child Operation Dependency Constraints

• Movement, Wait, or Transport Constraints

The main categories are detailed below:

Material Constraints

Production planning must account for actual material availability. Otherwise, planned orders without proper inventory visibility risk imminent stockouts.

The Opcenter APS considers different material sources:

• Available inventory in the current period;

• Purchase orders - already linked to suppliers;

• Purchase requisitions - not yet linked (internal documents).

Additionally, it is possible to:

• Define priority warehouses;

• Link inventory to specific work centers;

• Restrict consumption based on material quality, supplier, or batch.

Practical example:
In the textile industry, it is common to require that all production orders for a single customer order use the same batch of yarn to ensure color uniformity across garments. Even if the SKU and color are the same, slight variations in dyeing can compromise the quality of the final product.

Opcenter APS allows for different levels of risk in planning:

• More conservative: Sequence only with materials currently in stock.

• Moderate: Include purchase orders with safety margins.

• Simulated: Ignore shortages to analyze the plant's full production potential.

This flexibility supports simulations, internal benchmarking, and strategic decision-making.

Routing Constraints and Valid Resources

The production routing describes the steps a material goes through until it becomes a finished or semi-finished product. Ideally, each Part Number (SKU) has its routing registered in the ERP, which is the System of Record.

In Opcenter APS:

• Routings can be imported from the ERP or, in specific cases, created directly.

• Work centers are assigned according to the routing, restricting where each operation can take place.

Additionally, the APS allows you to:

• Restrict work centers based on product attributes (color, material type, etc.);

• Customize routings quickly for simulations and feasibility analyses, without affecting the ERP.

This capability is essential for industries that need to quickly simulate production planning and scheduling scenarios, dynamically adjusting routings and resource allocation.

Secondary Constraints

Real-world production systems are subject to numerous constraints beyond the capacity of so-called primary resources (machines, work centers, production lines). These additional constraints include:

• Specialized labor;

• Available electrical power;

• Tooling, molds, and dies;

• Shared auxiliary resources.

These are referred to as secondary constraints in Opcenter APS—essentially, any other element that impacts the production system's capacity. Consequently, the models created using APS in projects implemented by NEO Digital Industries include the ability to configure these constraints, ensuring high accuracy and realism in the model.

Practical example:
Imagine a hypothetical factory F with 3 machines available 5 days a week, 8 hours a day, totaling 120 hours of weekly capacity.  

Demand for product A is 100 hours, and it can be processed on any machine. However, product A requires the use of die X—and the factory only has 2 of die X, which restricts the available capacity to 80 hours.

In other words, even with sufficient nominal machine capacity, the die bottleneck prevents full demand fulfillment.

With Opcenter APS, you can model these constraints and generate schedules and sequences that truly reflect the reality of your factory floor.

Other Advanced Constraints

The Opcenter APS sequencing module also handles more complex constraints, such as:

• Production order synchronization (dependent operations);

• Controlled parallelism between work centers;

• Movement between production areas, considering:

• Transport times,

• Mandatory wait times,

• Logistics capacity constraints.

• Minimum or maximum batch constraints;

• Custom calendar and shift constraints.

These features allow the factory model in APS to accurately reflect the actual production environment, supporting fast, intelligent, and feasible decision-making.

Conclusion

Opcenter APS goes beyond basic material and routing constraints, integrating advanced features that allow you to:

• Model secondary and auxiliary constraints,

• Simulate different risk levels,

• Optimize sequencing based on the specific reality of each operation.

Want to understand how these constraints can be modeled for your business?
Talk to our experts at NEO Digital Industries: https://www.neodigitalindustries.com/contato