As an experienced consultant in implementing ISA-95, we can prepare a guide to Information Flow similar to the below-mentioned table:
| Source Level | Target Level | Type of Information Exchanged (ISA-95 Context) | Typical Form / Protocol | Notes & Enhancements |
|---|---|---|---|---|
| ERP (Level 4) | MES / MOM (Level 3) | – Production Schedules – Work Orders – Product Definitions – Material Lists | B2MML (XML/JSON) over APIs (REST, SOAP) or Messaging (MQ) | B2MML implements ISA-95 models. High-level KPIs are usually derived from L3 data, not sent down from L4. |
| MES / MOM (Level 3) | ERP (Level 4) | – Production Responses – Completed Quantities – Material Consumption – Quality Test Results | B2MML (XML/JSON) over APIs or Messaging | Inventory updates result from this consumption/production information. |
| MES / MOM (Level 3) | SCADA / Control (Level 2) | – Detailed Procedures / Recipes – Setpoints – Operator Instructions – Work-to-Packets | OPC UA (Commands/Recipes), MQTT/Sparkplug | Dispatch instructions decomposed into executable “work packets.” REST less common due to real-time requirements. |
| SCADA / Control (Level 2) | MES / MOM (Level 3) | – Production Performance (per batch/unit) – Contextualized Alarm & Event Summaries – Aggregated Equipment Status | OPC UA (Alarms & Events, Data), MQTT/Sparkplug | Contextualized data; “as-produced” records. MES calculates KPIs from this data. |
| Control / PLC (Level 1) | SCADA (Level 2) | – Raw Sensor Readings (I/O) – Actuator States – Device-level Alarms | OPC DA/UA, Fieldbus (Profinet, EtherNet/IP), Modbus TCP | Raw, real-time data layer with strict timing. SCADA aggregates/contextualizes for L3. |
| SCADA / Control (Level 2) | PLC (Level 1) | – Device Commands – Control Setpoints – Mode Changes | Fieldbus, OPC UA | Added downflow: L2 sends commands based on recipes from L3. Critical for execution. |