Short, clear
definitions.

Apache Kafka is a distributed event streaming platform that durably writes events to partitioned topics and delivers them to several consumers.

A CMMS (Computerized Maintenance Management System) manages assets, maintenance plans and work orders; SAP PM is an example.

A data contract is a written agreement between source and consumer on the fields, types, units, time and quality rules and owner of a data flow.

A digital twin is a virtual representation of a machine, line or process fed with real-time shop-floor data and used for monitoring, simulation and analysis.

Edge computing means processing data on a device close to where it is produced instead of on a central server or in the cloud.

ERP (Enterprise Resource Planning) is an enterprise system that manages business processes such as finance, procurement, inventory, sales and production planning in one piece of software.

A historian is a time-series-oriented data system that records process values at high speed with timestamp and quality information and stores them for a long time.

Idempotency means that performing the same operation more than once does not change the outcome; in integration it keeps retries from producing duplicate records.

IT/OT integration means exchanging data between information technology (IT) systems such as ERP, databases and cloud and operational technology (OT) systems such as PLCs, SCADA and machines.

MES (Manufacturing Execution System) manages and records how production orders are executed on the plant floor and keeps material, equipment, quality and traceability information.

MQTT is a lightweight publish/subscribe messaging protocol that works through a broker; it was designed for constrained devices and unreliable networks.

MQTT QoS (quality of service) sets a message’s delivery assurance: QoS 0 delivers at most once, QoS 1 at least once and QoS 2 exactly once.

OEE (Overall Equipment Effectiveness) is availability × performance × quality and shows how much of the planned production time turned into good product.

OPC UA (OPC Unified Architecture) is an industrial communication standard (IEC 62541) for platform-independent, secure and object-based data exchange between machines, PLCs and higher-level systems.

A PLC (programmable logic controller) is an industrial computer that reads input signals and drives outputs through a cyclically executed program to control machines and processes.

A REST API is an application interface that gives access to resources over HTTP (with methods such as GET, POST, PUT and DELETE) and mostly uses JSON.

A BAPI (Business Application Programming Interface) is a standardised interface, callable through RFC, for working with SAP business objects; RFC (Remote Function Call) is the SAP protocol that makes the call possible.

An IDoc (Intermediate Document) is the standard segment-based document format SAP uses for asynchronous data exchange between systems.

SCADA (Supervisory Control and Data Acquisition) is a system that collects data from field PLCs and devices and gives operators monitoring, alarms, trends and supervisory control.

Sparkplug B is an open industrial specification (Eclipse Sparkplug) that defines topic naming, a Protobuf-based payload format and device state management (birth/death certificates) on top of MQTT.

Store & Forward is a buffering approach in which data is stored locally while the destination is unreachable and forwarded in order when access returns.

Time-series data is a sequence of measurement or event records ordered by timestamp; sensor, counter and process values are usually stored this way in industry.

Production traceability is the ability to trace back which material, equipment, process parameters and time a product or batch was produced with.

A Unified Namespace (UNS) is an architectural approach that publishes a plant’s current state and events in a single hierarchical namespace, usually implemented with an MQTT broker.