RMDB vs Siemens Opcenter APS: Manufacturing Scheduling Comparison

Comparing RMDB and Siemens Opcenter APS is really a comparison between two different approaches to solving the same problem. Siemens Opcenter APS (formerly Preactor) is an enterprise-grade scheduling platform backed by one of the world's largest industrial technology companies. RMDB is a focused finite capacity scheduling tool built over 35 years by User Solutions specifically for small to mid-size manufacturers. Both deliver genuine scheduling intelligence — but at dramatically different price points, implementation timelines, and complexity levels.

This comparison is not about which software is "better" in absolute terms. It is about which fits your operation. For the full landscape of scheduling tools, see our production scheduling software comparison guide.

Company Background

Siemens Opcenter APS

Siemens Opcenter APS has its roots in Preactor, a UK-based APS company founded in 1992 that became one of the most widely deployed scheduling solutions globally. Siemens acquired Preactor in 2013 and integrated it into the Opcenter portfolio, which also includes MES (Opcenter Execution), quality management, and manufacturing intelligence. With Siemens' resources behind it, Opcenter APS is now positioned as part of a comprehensive digital manufacturing platform.

Opcenter APS comes in multiple tiers — Express, Standard, and Advanced — each adding scheduling sophistication and optimization capabilities.

RMDB by User Solutions

RMDB is developed by User Solutions, founded in 1991 with over 35 years of experience in manufacturing scheduling. RMDB is a dedicated finite capacity scheduling and planning system designed to work alongside any ERP. The software serves manufacturers across aerospace, defense, automotive, electronics, heavy equipment, and job shop machining.

Feature Comparison

Scheduling Engine Comparison

Both RMDB and Opcenter APS are genuine APS systems with finite capacity scheduling engines. The differences lie in optimization depth, scalability, and ecosystem integration.

Opcenter APS Scheduling Capabilities

Opcenter APS offers a tiered capability model:

• Express: Basic forward/backward scheduling with capacity visualization. Suitable for simple scheduling needs.
• Standard: Adds multi-constraint scheduling, what-if scenarios, and more sophisticated dispatching rules.
• Advanced: Full optimization with heuristic algorithms, linear programming, and the ability to optimize across multiple objectives simultaneously (due date adherence, setup minimization, resource utilization).

The Advanced tier represents one of the most sophisticated scheduling engines on the market. It can handle thousands of operations across hundreds of resources with complex constraint networks. For very large manufacturers, this level of optimization translates into measurable throughput improvements.

RMDB Scheduling Capabilities

RMDB provides advanced finite capacity scheduling with multi-constraint optimization, what-if scenario analysis, sequence-dependent setup handling, and interactive Gantt-based planning through EDGEBI. The scheduling engine considers machine capacity, labor skills and availability, tooling constraints, and material availability simultaneously.

For the scheduling scenarios that small to mid-size manufacturers encounter — 10 to 100 machines, hundreds to thousands of active orders, multiple constraints, and frequent rescheduling — RMDB's scheduling engine delivers results comparable to the mid-tier Opcenter offerings. The difference emerges primarily in very large-scale optimization problems with thousands of resources.

The Ecosystem Factor

The most significant difference between RMDB and Opcenter APS extends beyond the scheduling engine itself.

Siemens Digital Enterprise Ecosystem

Opcenter APS is part of Siemens' broader Xcelerator portfolio, which includes:

• Opcenter Execution (MES): Shop floor execution and work-in-process tracking
• Opcenter Quality: Quality management and SPC
• Opcenter Intelligence: Manufacturing analytics and reporting
• Teamcenter PLM: Product lifecycle management
• NX/Tecnomatix: Digital twin and simulation

For manufacturers already invested in the Siemens ecosystem — or planning to adopt it — Opcenter APS provides seamless integration across the entire digital manufacturing stack. This integration is a genuine differentiator for large enterprises pursuing comprehensive digital transformation.

RMDB: Focused and Flexible

RMDB takes the opposite approach: do one thing exceptionally well and integrate with everything else. Rather than locking you into a single vendor's ecosystem, RMDB connects to whatever ERP, MES, or quality system you already use. This flexibility means you can adopt best-in-class tools for each function rather than compromising on an all-Siemens stack.

For manufacturers who are not Siemens shops — and most small to mid-size manufacturers are not — RMDB's vendor-agnostic approach is a significant practical advantage.

Pricing: An Order of Magnitude Apart

The cost difference between RMDB and Siemens Opcenter APS is not incremental. It is an order of magnitude.

Siemens Opcenter APS Pricing

Opcenter APS pricing is not publicly listed and varies based on tier, modules, users, and negotiation. Based on industry data:

• Opcenter APS Express: $15,000-$40,000 (limited scheduling)
• Opcenter APS Standard: $75,000-$150,000
• Opcenter APS Advanced: $150,000-$500,000+
• Implementation services: $50,000-$250,000
• Annual maintenance: 18-22% of license cost
• Typical total first-year cost: $150,000-$750,000

RMDB Pricing

• One-time perpetual license: $5,000-$15,000
• 5-day implementation: Included
• Optional annual maintenance: Fraction of license cost
• Typical total first-year cost: $5,000-$15,000

5-Year Total Cost of Ownership

For a 75-person job shop, that cost difference funds significant capital equipment purchases, additional hires, or other operational improvements.

Implementation: A Week vs a Year

RMDB: 5 Business Days

User Solutions' 5-day implementation loads your actual production data and has planners scheduling live jobs by end of week one. The narrow focus on scheduling — without MES, quality, or PLM dependencies — makes this rapid deployment possible.

Opcenter APS: 6-18 Months

Enterprise APS implementations follow a methodical process: requirements gathering, data mapping, integration development, configuration, testing, training, and phased rollout. With Opcenter, the integration requirements with existing ERP and potentially MES systems add significant complexity. Implementations of 6-12 months are standard, and 18-24 month timelines are not unusual for multi-module deployments.

This is not a shortcoming of Siemens or its implementation partners. Enterprise software deployments are inherently complex. The question is whether your operation requires enterprise-scale implementation or whether a focused scheduling tool can solve your problems in a week.

When Siemens Opcenter APS Is the Better Choice

Opcenter APS makes sense when:

• You are a large enterprise (500+ employees) with the budget and IT resources for enterprise software.
• You are already invested in the Siemens ecosystem (Teamcenter, NX, Opcenter MES) and want native integration across the digital thread.
• You need multi-plant scheduling with complex inter-facility dependencies and supply chain synchronization.
• You require advanced optimization for very large scheduling problems with thousands of resources and operations.
• You are pursuing comprehensive Industry 4.0 digital transformation and want a single vendor for your manufacturing operations stack.

When RMDB Is the Better Choice

RMDB is the stronger fit when:

• You are a small to mid-size manufacturer (10-500 employees) who needs scheduling intelligence without enterprise overhead.
• Budget is a real consideration. At 90%+ lower cost than Opcenter APS, RMDB makes advanced scheduling accessible to manufacturers who could never justify enterprise APS pricing.
• You need results fast. If late deliveries are costing you customers today, waiting 6-18 months for an APS implementation is not viable. RMDB's 5-day implementation addresses urgency.
• You are not a Siemens shop. If your ERP is Epicor, SAP Business One, JobBOSS, Sage, or any other non-Siemens platform, RMDB's vendor-agnostic approach provides cleaner integration.
• You run a job shop where scheduling complexity is high but the scale does not justify enterprise APS.
• You want to own your software with a one-time license rather than perpetual subscription or maintenance obligations.

Honest Bottom Line

Siemens Opcenter APS is a world-class scheduling platform with deep optimization capabilities and unmatched ecosystem integration within the Siemens stack. For large manufacturers pursuing Siemens-centered digital transformation, it is a logical choice.

For the vast majority of small to mid-size manufacturers, Opcenter APS is like buying a Formula 1 car to commute to work. The capability is there, but the cost, complexity, and maintenance requirements are wildly disproportionate to the need. RMDB delivers the finite capacity scheduling, visual Gantt planning, what-if analysis, and constraint management that most manufacturers need — in a week, at a fraction of the cost, without locking you into any ecosystem.

Both are good tools. The right one depends on your scale, budget, and strategic technology direction.

Frequently Asked Questions

Compare RMDB Against Enterprise APS With Your Data

Enterprise APS vendors show impressive demos with sample data. We show results with your data — in five days. Contact User Solutions to schedule a demo using your actual jobs and constraints. See what your schedule looks like when finite capacity intelligence is applied to your real-world complexity. Request your demo today.