AdvancedSiemens Opcenter Execution (MES)Opcenter Execution Foundation / Discrete / Process

How to Add AI to Siemens Opcenter Execution (MES) On-Prem

Question
how to add AI to Siemens Opcenter Execution on-prem

Also searched as

  • Opcenter Execution AI integration without cloud
  • Camstar MES AI assistant on-prem
  • Opcenter Execution Foundation API read-only
  • private LLM for Siemens MES data

Short answer

Opcenter Execution is a family with different data models, so start by identifying your variant (Foundation, Discrete or Process) and its supported service and reporting interfaces. Read through those, or through a reporting copy of the database, behind a read-only tool server. Serve an open-weight model on local GPUs and send any write-back through the MES's own transactions with approval.

Applies to: Opcenter Execution Foundation (Camstar lineage), Opcenter Execution Discrete and Opcenter Execution Process, on-prem. Interfaces and database engines differ by variant and version; confirm against Siemens documentation for your release.

Reference build, in order

  1. 1Identify exactly which Opcenter Execution variant and version you run, and which database engine hosts it.
  2. 2List the supported read interfaces for that version: service APIs, the integration product your plant uses, and reporting views or a reporting database maintained by Siemens or your integrator.
  3. 3Create a read-only identity and, where the data model is heavy, stand up a replicated reporting copy for analytical questions.
  4. 4Define the business objects the assistant needs (lots or containers, work orders, operations, resources, specs, nonconformances, history) and map each to one read operation.
  5. 5Index MES-adjacent documents (work instructions, SOPs, deviation records) with source permissions.
  6. 6Serve an open-weight model with vLLM or Ollama on local GPUs and connect it only to the tool server.
  7. 7Mirror MES roles, factories and resource groups into allow lists and log every call.
  8. 8Roll out read-only, then drafted outputs, then approved MES transactions through the supported interface.

Know your variant before you design anything

Opcenter Execution Foundation comes from the Camstar platform and is a model-driven system: factories, products, specs, workflows, resources and containers (lots) are configured as objects, and every shop-floor transaction is recorded against them, producing history for traceability. Opcenter Execution Discrete and Process are different products with their own data models, and Siemens documents integration points for each.

Because of that, a generic list of table names would be wrong for some readers. The reliable approach is mechanism-first: use the supported service APIs for transactional and object reads, use the Opcenter reporting and intelligence offerings or a reporting copy for analytical reads, and have your integrator document the views you will rely on.

For ERP connectivity, Siemens offers an integration layer (Opcenter Connect MOM) that plants commonly use to exchange orders and confirmations with ERP; if you have it, it also tells you how orders and lots map across systems.

# Pseudo-request to a tool server operation (shape only; the underlying call uses your version's documented service API)
POST https://ai-tools.plant.local/tools/get_lot_history
{
  "lot_id": "L-2026-004512",
  "max_events": 200,
  "include": ["operations", "resources", "nonconformances"]
}

# The tool server maps this to a read-only call against the supported API or reporting copy,
# enforces the caller's factory and resource-group allow list, and returns a compact summary.

Reference architecture

Run the AI stack beside your MES reporting tier. A read-only reporting copy (or a read replica where your database engine and Siemens support it) keeps analytical questions off the transactional database that operators depend on. The tool server calls supported APIs for object lookups and the reporting copy for aggregates.

The retrieval index holds work instructions, specs descriptions, deviation and CAPA documents, and an export of MES configuration names (products, operations, resources) so users can ask in plain terms. Keep the lot and WIP data itself out of the index and read it live through tools.

In an air-gapped plant, the whole stack runs unchanged on your own servers, with models and containers loaded from approved media and logs kept in the isolated zone.

Permissions and traceability obligations

MES roles typically scope what users can do per factory, operation or resource group. The assistant should carry the user's identity into the tool server and apply the same scoping to every lookup and every retrieved document. If the MES cannot be called as the user, fall back to a service identity with an allow list derived from the user's roles.

Regulated plants (aerospace, defense, medical devices) have record-integrity and traceability duties. The assistant should be read-only against the electronic record, and any information it produces should be clearly labelled as a draft that is not part of the controlled record until a person commits it.

Keep an audit trail of questions, sources and tool calls so you can show who looked at which lot data and when.

Write-back, sizing and phases

Write only through MES transactions exposed by the supported interface, with a person approving the exact payload: for example opening a nonconformance, adding a comment to a lot, or placing a hold. Never insert or update MES tables directly, which would bypass business rules and history.

As a range, one 24 to 48 GB GPU serves tens of occasional users; hundreds of active users usually need two to four GPUs. The document index for tens of thousands of files is a few GB to low tens of GB.

Phase 1: read-only lot, WIP and nonconformance questions for one factory. Phase 2: drafted deviation reports and shift summaries. Phase 3: approved holds, comments and requests via the MES's own transactions.

Limits and when Siemens tools are enough

If your users need standard operational reporting, Opcenter's own reporting and intelligence tools may cover it, and the assistant is optional. The AI layer helps when questions cross systems (MES, ERP, quality documents), or when users cannot be expected to know the data model.

Expect integration effort to be heavier than for SQL-first SCADA systems because the data model is rich and version-specific. Do not over-promise a single answer across MES and ERP until each read operation is tested. Siemens also offers its own AI-related features; evaluate them first if your data policy allows.

Try it here, free

Siemens Opcenter Execution AI Assistant Sizing and Value Calculator

Open full tool

Estimate peak concurrency, GPU count, index size, hours saved and payback for a private on-prem AI assistant on Siemens Opcenter Execution.

Common pitfalls

  • !Designing against table names from a blog post that match a different Opcenter variant or version.
  • !Querying the transactional MES database for analytical questions during production.
  • !Writing to MES tables directly instead of using supported transactions, which breaks history and business rules.
  • !Presenting AI-drafted text as part of the controlled electronic record.
  • !Ignoring factory and resource-group scoping in retrieved documents.
  • !Indexing live WIP data, which goes stale within minutes. Read it through tools instead.

How an ERP-grounded AI assistant handles this

Netray builds the tool server and retrieval layer against the interfaces you approve, and joins MES data to ERP records through ERPray so a held lot can be tied to its work order, supplier lot and open purchase order. Sources and tool calls are shown to the user.

See ERPray

Frequently asked questions

Is Opcenter Execution Foundation the same as Camstar?

Foundation descends from the Camstar platform, but product names and versions have changed over the years. Always confirm interfaces and database details for your specific release in Siemens documentation.

Can we read the database directly?

Only through views or a reporting copy that Siemens or your integrator has documented for your version, and only read-only. Prefer the supported APIs for object lookups, and never write to the tables.

How do we keep records compliant?

Keep the assistant read-only against the controlled record, label its output as draft, and commit changes only through MES transactions that a person approves, so history and electronic signatures stay intact.

Can it work air-gapped?

Yes. Models, embeddings, the index, the tool server and the audit log all run on your own servers, with software brought in on approved media.

Related

Advanced

How to Connect OPC UA Machine Data to Your ERP

Do not connect OPC UA servers straight to the ERP. Read machine tags through an edge gateway or MES, convert signals into business events (cycle complete, stop, state change, count), attach the work order context, and post summarised confirmations to the ERP through its supported API. The ERP wants quantities, times and reasons per order, not millions of raw tag values.

How-to

How to Calculate OEE from MES Data and ERP Standards

OEE equals Availability times Performance times Quality. Availability comes from MES run and stop events against planned production time, Performance compares actual output to the ideal cycle time (usually the routing standard from the ERP), and Quality is good units divided by total units. The numbers are only trustworthy if planned time, ideal cycle time and the good/scrap split are defined once and used consistently.

Advanced

How to Add a Private AI Layer to Rockwell FactoryTalk On-Prem

FactoryTalk is a family, so pick the read surface per product: Historian SE through its PI-based interfaces, View SE alarm and event logs through the SQL database, ProductionCentre through its documented interfaces, and VantagePoint where you already consolidate data. Put a read-only tool server in front, serve an open-weight model locally, and respect FactoryTalk Security.

How-to

How to Send Production and Labor Reporting from MES to ERP

Treat the ERP work order as the system of record for cost and quantity, and the MES as the system of record for what physically happened. Send one confirmation message per operation (or per shift or lot) containing work order, operation sequence, good quantity, scrap quantity with reason, and labor start/stop per employee and work center, post it through the ERP's supported transaction API, and make the message idempotent so a retry never double-posts.

Advanced

ISA-95 and B2MML: How to Integrate ERP with MES

ISA-95 defines the boundary between business systems (Level 4, the ERP) and manufacturing operations (Level 3, the MES) and the information that crosses it. B2MML is the XML implementation of those models. In practice you exchange a ProductionSchedule from ERP to MES, and ProductionPerformance, plus material and equipment information, back, mapping each element to your ERP's work order and confirmation APIs.

How-to

How to Design Scrap and Downtime Reason Codes for MES and ERP

Keep one governed list of reason codes with a small hierarchy, owned in a single system and synchronised to the other. Separate scrap reasons from downtime reasons, mark each downtime code planned or unplanned and each scrap code as process, material, design or operator related, and map codes to ERP accounts or cost categories where accounting needs them. Fewer, clearer codes beat long lists nobody uses correctly.

AI for ERP

AI for SAP Plant Maintenance: Notifications, Work Orders, and Predictive Signals

AI grounded on SAP PM data that triages notifications, drafts work orders, standardizes failure codes, and flags predictive maintenance signals, on-prem.

AI for ERP

AI for Plex Manufacturing Cloud, Grounded in Your Production Data

Put AI on Plex production, quality, and genealogy data without a public model. On-prem or private-cloud LLMs, RAG, and agents built for Plex shops.

Stuck on Siemens Opcenter Execution (MES)?

Talk to engineers who work inside Siemens Opcenter Execution (MES) every week, and who build private AI that answers these questions from your own ERP data.

Talk to an ERP engineerBrowse ERP Help
All ERP Help articles

Keep exploring

Free tools

ERP fixes and how-tos

AI on your ERP

Comparisons

Software

TermsManufacturing Execution System (MES)