MES study guide
MES · Work through your exam, one topic at a time.
The MES credential is aimed at professionals who work with Manufacturing Execution Systems - the software layer that sits between ERP planning and the plant floor, dispatching work orders, collecting process and quality data, enforcing specifications, and tracking materials and equipment in real time. Typical candidates are production or operations engineers, MES administrators and configurators, quality and validation specialists, automation and IT/OT integration engineers, and shop-floor supervisors moving into system ownership. The MES study guide has 9 sections and about 2,501 words.
01Manufacturing Execution Systems Fundamentals
This domain tests the boundary between business planning and plant-floor control: ISA-95 levels, MES functional scope, order execution, genealogy, and how MES differs from ERP and SCADA. ISA-95 separates Level 4 business planning, Level 3 manufacturing operations management, Level 2 monitoring/supervisory control, Level 1 control, and Level 0 physical process.
287 words, about 1 min02Production Operations Management
This domain covers turning released orders into a feasible sequence: finite and infinite scheduling, dispatching rules, takt, bottlenecks, work-in-process control, setup effects, and cycle-time management. Takt time = available production time / customer demand.
261 words, about 1 min03Quality Management
Quality questions focus on in-process controls: SPC, specification versus control limits, capability indices, nonconformance handling, CAPA, sampling, holds, and quality gates. Control limits come from process variation, usually mean +/- 3 sigma.
279 words, about 1 min04Inventory and Material Tracking
This domain tests lot and serial traceability, material status, location control, issue and backflush logic, cycle counting, and genealogy from receipt through shipment. Lot control groups material by a common production or receipt event; serial control identifies individual units.
281 words, about 1 min05Equipment and Maintenance Management
Expect questions on OEE, downtime classification, preventive and predictive maintenance, work orders, calibration, MTBF, MTTR, and the difference between equipment effectiveness and overall plant effectiveness. OEE = availability x performance x quality.
271 words, about 1 min06Data Collection and Integration
This domain tests how MES acquires and contextualizes plant data: PLC and SCADA integration, OPC UA, MQTT, REST, historians, barcode/RFID, time synchronization, and message reliability. PLCs provide control-level signals; SCADA supervises equipment; historians store time-series data; MES adds order, material, personnel, and quality context.
290 words, about 1 min07System Architecture and Configuration
This domain covers MES deployment structure: ISA-95 equipment hierarchy, servers and high availability, network segmentation, master data, configuration versions, environments, and workflow design. The ISA-95 equipment hierarchy commonly runs enterprise, site, area, work center, work unit, and equipment.
265 words, about 1 min08Regulatory Compliance and Validation
This domain tests GMP-oriented computer system validation and data integrity: GAMP 5 risk-based validation, IQ/OQ/PQ, 21 CFR Part 11, EU Annex 11, audit trails, electronic signatures, and change control. Validation demonstrates that a system consistently meets intended use.
284 words, about 1 min09Reporting, Analytics, and Continuous Improvement
This domain tests KPI definition and use: OEE, first-pass yield, scrap, cycle time, throughput, downtime Pareto, dashboards, data lineage, and improvement methods such as DMAIC. Define KPIs with numerator, denominator, time window, and scope.
283 words, about 1 min