MESManufacturing Execution System

A Manufacturing Execution System (MES) is the software that runs the shop floor between the ERP layer (which knows the plan and the money) and the equipment layer (PLCs, weigh stations, vision systems, IoT sensors). The MES is where the operator interacts with work — it dispatches the task, presents the controlled procedure, captures every step, validates the inputs against specification, records the outputs, signs them, and posts the result back to ERP.

MES emerged in the mid-1990s when industry realised the gap between the ERP layer and the equipment layer was where most quality and productivity were lost. AMR Research coined "MES" in 1992 to describe the missing middle. ISA-95 (released in 2000, current edition 2010) standardised the reference model. MESA International codified the 11 (later 12) functions of an MES.

ISA-95 organises manufacturing IT into five levels. The MES — formally "Manufacturing Operations Management (MOM)" in ISA-95 vocabulary — lives at Level 3, between Level 2 (control systems: SCADA / DCS / PLC) and Level 4 (ERP / business planning).

Real plants do not honour the ISA-95 levels cleanly. A modern MES often reaches down to Level 2 (reading PLC tags directly via OPC UA) and up to Level 4 (consuming ERP work orders, returning yield). What ISA-95 really gives you is a common vocabulary for who owns what — so when the question is "where does scheduling live?" or "who owns lot genealogy?" everyone has the same map.

MESA International originally defined 11 MES functions, expanded to 12 in the 2008 model. They are still the cleanest functional inventory of what an MES owns on the shop floor.

MES requirements vary sharply by industry. The same platform has to handle three quite different execution profiles.

Process

Pharma, food, supplements, cosmetics, ingredients, sausage/meat, beverages, paint, lubricants. Recipe + batch driven. ISA-88 is the reference model. Yield is mass-based; scrap is rework or waste. Allergens, campaigns, equipment cleaning, environmental monitoring and shared-vessel sequencing dominate scheduling. The MES record is the BMR / BPR.

Discrete

Medical devices, consumer products, electronics, industrial assembly. Bill of Material driven. ISA-95 is the reference. Yield is counted in units. Serialised genealogy (which sub-assembly, with which firmware, in which finished unit) dominates. The MES record is the DHR or unit-level traveller.

Hybrid

Most real plants. Pharma packaging is discrete (counting bottles), pharma bulk is process. Medical-device sub-assembly may include sterilisation that is a process step. Plants need an MES that switches modes per work order, with different records and different release rules.

A non-regulated MES (automotive, electronics, light industry) optimises for throughput, OEE and traceability. A regulated MES has to do the same — and also produce an inspector-ready record.

• 21 CFR Part 11 / EU Annex 11 — electronic records, e-signatures, secure timestamps, password discipline, signature meaning, audit trail.
• Two-person e-signature on critical operations (recipe approval, batch release, formula change). 21 CFR 11.200, 211.186, 111.205.
• Immutable record bound to the procedure version in force at execution time. Edits create a new version, not an overwrite. ALCOA+.
• Hard gating on training — operator with overdue assigned training cannot start the task. 21 CFR 211.25, 820.25, ISO 13485 §6.2.
• Hard gating on calibration — equipment past calibration due-date cannot be used. 21 CFR 211.68, 820.72.
• Change-control aware — a procedure revision invalidates in-flight work or forces re-issue with the new version.
• Validated to GAMP 5 / CSV — URS, IQ, OQ, PQ, traceability matrix, periodic review.

These are not optional features; they are the difference between an MES regulators trust and one that becomes a 483 observation in the next inspection.

ISO 22400 lists 34 standard KPIs for manufacturing operations management. The headline ones every plant tracks:

• OEE (Overall Equipment Effectiveness) = Availability × Performance × Quality. World-class is 85 %; pharma packaging often runs 40–60 %.
• Throughput — units per shift / day / week per line.
• Yield — good units out of total units started.
• First Time Right (FTR) — proportion of batches / devices released without rework or deviation.
• Cycle time — order release to release.
• Schedule attainment — planned vs actual completion.
• Scrap and rework rate.
• Downtime by cause (planned, unplanned, changeover, breakdown, cleaning, waiting).
• Energy per unit produced — increasingly a sustainability KPI.
• Quality cost — internal failure + external failure + appraisal + prevention.

The traditional pharma / life-sciences MES market has been dominated by Werum PAS-X (Körber), Rockwell PharmaSuite, Honeywell POMS / Discoverant, Siemens Opcenter and Emerson Syncade. These are heavy, enterprise-grade systems that ship with the depth pharma needs and the timeline (12–24 months) and cost (mid-7-figure first deployments) to match.

The newer wave — Tulip, Apprentice, L2L, Plex (Rockwell), Critical Manufacturing, V5 Ultimate — bets on cloud, low-code / no-code authoring, faster time to value, and tighter integration of QMS / LIMS / eBMR into the same record. The convergence is unmistakable: classic MES vendors are extending into quality; classic eQMS vendors (MasterControl, Veeva) are extending into execution. Buyers are voting for fewer integrations.

ISA-95 still rules the architectural conversation, but real systems blur the levels. OPC UA, MQTT and Sparkplug make Level-1/2 data trivial to bring into Level 3; cloud and SaaS architectures make Level 3 / Level 4 distinction more about ownership than location.

1. Does it support your execution profile (process, discrete, hybrid) natively — or are you forcing one model into the other?
2. 21 CFR Part 11 / Annex 11 e-signature, audit trail and ALCOA+ behaviour native or bolted on?
3. Two-person e-signature on the critical steps for your industry — and is the operator role separation enforced?
4. Does it gate on training, calibration and change control automatically, or only with custom configuration?
5. Validated platform — does the vendor ship URS / IQ / OQ test scripts you can leverage?
6. Recipe / MMR / DMR authoring — how versioned, how approved, how locked once released?
7. Real-time data acquisition — OPC UA, MQTT, REST, scales / vision integration — out of the box?
8. OEE, downtime, yield, FTR — calculated from events or requires manual data entry?
9. Does it host the BMR / DHR / batch record natively, or feed a separate system?
10. Closed loop with QMS — does a deviation captured here open a CAPA there with one click?
11. Multi-site, multi-tenant, multi-language?
12. Time to first batch in production — 8 weeks or 18 months?

V5 Ultimate is an MES — and more than an MES. The shop-floor execution layer (dispatch, kiosk, dispense, in-process check, deviation, hold, release, genealogy, OEE) is wired to the QMS spine (document control, training, change control, CAPA), the LIMS layer (sample, instrument, OOS / OOT, CoA), the WMS layer (bin-level inventory, putaway, dispense, transfer), and the eBMR / eDHR record. One database. One audit trail. One ALCOA+-compliant record.

Because V5 covers all three execution profiles — process, discrete, hybrid — the platform supports recipe-driven pharma batches, BOM-driven device assembly, and the hybrid packaging / sterilisation steps that span them. Industry-aware kiosk tiles, sidebar navigation and report terminology come from the workspace's execution profile, not hard-coded language.