Service · Software development

Custom MES development.

A custom Manufacturing Execution System for discrete manufacturing, process industries and hybrid production environments. Production orders, OEE, andon, quality and traceability in one layer between your ERP and the shop floor, built around your own routings, PLC stack and compliance requirements rather than around a standard package that fits 60%.

Arrange an introductory call See our work

A MES is the layer between the ERP and the shop floor.

A Manufacturing Execution System, or MES for short, is the execution layer of the factory. Your ERP plans: which orders need to be made when, which materials are required, which capacity is available. Your PLCs and SCADA control the individual machines and sensors. The MES sits precisely in between and answers the operational question: which order is running on which machine right now, with which operator, which material batch and which quality, and how that relates to the plan coming from the ERP.

For enterprise environments, mature standard packages exist, such as Siemens Opcenter, Rockwell FactoryTalk, GE Proficy, Plex MES, Aegis FactoryLogix, MPDV HYDRA and SAP DM/ME. We are honest about this: these platforms have been developed over decades, and we do not replace them for deep enterprise implementations. We are asked in situations where a standard package does not fit, because the processes are hybrid, because industry-specific compliance demands deviating flows, because the PLC stack speaks legacy protocols the package does not support, or because operators need to work on a tablet or HMI rather than a fixed terminal.

For those situations we build a custom MES: an execution layer that fits your routings, machines, operator skills and compliance requirements exactly, and connects seamlessly with the ERP you already use and the PLC/SCADA layer you already have in place. No per-machine licence lock-in, no annual module price list, and the freedom to build an external API integration or a legacy protocol integration where a standard package won't go.

Our approach in four points.

Routing first

We model your production routings and operations before we build

Shop-floor focused

An operator app on tablet or HMI is always part of the scope

Deep integration

Integrations with PLC, SCADA, OPC UA, MQTT and your ERP

Ownership

Code, infrastructure and knowledge remain with your organisation

Which MES projects we build.

MES implementations differ greatly by sector and production type. We are usually asked for three patterns, and a project almost always combines two of them.

Engagement 01

Sector-specific MES for process and discrete manufacturing

Compliance, batches and traceability in one layer

For manufacturers where compliance dictates the workflow: pharmaceutical production under GMP, food industry under HACCP, aerospace suppliers under AS9100, or medical devices under ISO 13485. A MES that captures batch records completely, supports electronic signatures where regulation requires them, and provides exact traceability from raw material to finished product.

The gain is twofold. Operationally: fewer paper work orders, no manual Excel step for audits, and real-time visibility of critical process steps. Compliance: reports that come out in the regulator's format, without a quality manager having to piece together data from three systems afterwards. We often combine this with a broader manufacturing software stack in which the MES is the execution layer within a wider platform for planning, quality and service.

Batch recordsLot and serial tracingElectronic signatureGMP/HACCPSPCAudit trail

Engagement 02

MES for discrete manufacturing and hybrid production

Line, assembly and test in one system

For manufacturers in metal, plastics, electronics and automotive that don't have just one type of production but a mix: partly line production with machine cycles, partly manual assembly with work instructions, partly final testing with measurement data. Standard MES packages usually rely on a single production type. We build a data model that serves all three side by side, without operators having to switch between screens.

In practice, that means an MES that dispatches production orders to CNC machines (with cycle times pulled from OPC UA), to assembly cells (with work instructions, photos and checklists on a tablet) and to test benches (with measurement data as the pass/fail criterion). Routings are BOM-aware and support alternative operations when a machine is occupied or under maintenance. For the service side, which often depends on this, we extend the CMMS integration directly.

Discrete and lineBOM-aware routingsAlternative operationsOperator appAndonOEE

Engagement 03

Multi-site MES overlay across different ERPs

One MES, multiple plants, multiple ERPs

For groups with multiple production sites that have historically each run their own ERP, often SAP at one plant, Microsoft Dynamics at a second, AFAS or Infor LN at a third, but which still want a consolidated view of production output, OEE, quality and operator hours. A custom MES as an overlay layer is often the pragmatic route: one data model for production execution, with separate adapters to each ERP for planning input and actual-hours output.

The difference from an enterprise MES licence lies in flexibility and cost: you don't pay a licence per machine or per user, you get a data model that fits your group structure exactly, and you keep control over the pace at which you connect new sites. At the same time, the existing ERP layer per plant stays in place. We don't replace a working financial system; we place the execution layer on top of it.

Multi-ERP integrationGroup overviewSAP + Dynamics + AFASPer-factory adaptersReal-time KPIsScalable rollout

What you have at the end.

A working MES in production, plus everything around it to manage and extend it yourself.

Production + staging

Two environments, in your own cloud, on-premise or hosted with us.

Operator app and dashboards

Tablet or HMI app for operators, planner dashboard, management reporting.

Codebase + documentation

Full source code, build instructions, and data model and integration documentation.

Key-user training

Sessions for planners, quality managers and supervisors, video for operators.

Managed service (optional)

Monitoring, backups, security patches, ongoing development and expansion.

When a custom MES is the right choice.

Four patterns in which a standard package gets stuck and custom MES software adds value, based on the projects we see in practice.

Compliance

Industry requirements that don't fit a standard package

Pharma under GMP with dual-signature work orders, food manufacturing under HACCP with raw-material-to-end-product tracing, or aerospace supply under AS9100 with traceability per serial number. Standard MES packages partly cover this, but deviating steps or industry-specific recording requirements often call for costly customisation, if the vendor is even willing to build it.

Hybrid processes

Line, assembly and test in one production flow

Manufacturers that partly produce on a line, partly assemble by hand and partly test rarely find one package that serves all three equally well. A custom MES models routings that switch between machine-driven and operator-driven steps, so operators and planners don't have to switch between multiple systems.

PLC integration

Legacy protocols or a non-standard machine park

When your machine park is mixed, with modern equipment using OPC UA and MQTT alongside older installations using Modbus, Siemens S7, MTConnect or even serial connections, standard MES packages usually only cover the modern side. A custom MES builds the adapters your factory actually uses, rather than adapting your factory to the vendor's adapter list.

Shop-floor UX

Operators on tablet or HMI, not a fixed terminal

In modern production environments, a MES that only works on a fixed workstation terminal is a handicap. Operators moving around the cell, technicians walking the line or supervisors touring the factory need an interface that works on a tablet or HMI, with large buttons, photo and barcode scanning, and a UX designed for someone wearing safety gloves.

Modules that recur in almost every custom MES.

The building blocks we draw on. The combination and depth differ per project.

Orders

Production order dispatch

Receiving production orders from ERP plus ad hoc orders from the shop floor. Dispatch to the right machine or cell based on routing, material availability and operator skill. Real-time status per order: planned, released, in progress, completed, reported.

Routings

Operations and alternative routings

BOM-aware routings that define the correct sequence of operations per product. Alternative routings when a machine is occupied, under maintenance or out of service. Per operation: setup time, cycle time, required skill and quality checkpoints.

Allocation

Machine and operator allocation

Assigning operators to machines or cells based on skill matrix, certification and availability. Shift capacity planning with real-time reallocation when an operator or machine drops out. Includes alerts when an operator's certification is about to expire.

Andon

Andon and escalation

Andon alerts from the shop floor (quality, material, machine, assistance) with the amber-light flow from pull to response. Timely escalation by time and type, root-cause tracking per andon call, and aggregated reporting to spot recurring causes of downtime.

OEE

OEE and performance measurement

Overall Equipment Effectiveness in real time: availability from machine cycles and downtime, performance from cycle time versus standard, and quality from scrap and rework. Per machine, per shift, per order, with drill-down from plant level to individual operation.

Quality

Quality, FAI, FPY and NCR flow

First Article Inspection on new orders, First Pass Yield monitoring during production, and a structured non-conformance flow for deviations. Statistical process control (SPC) on measurable product parameters, with automatic alerts when values drift outside control limits.

Traceability

Lot, batch and serial tracing

Full traceability from raw material or ingredient to end product: which batch went into which order, which operator performed which operation, and which measurement belongs to which serial number. Essential for recall investigations, GMP audits or HACCP controls, and increasingly important for B2B customers who want to close their own audit trail.

Operator app

Operator app on tablet or HMI

Digital work order on a tablet or fixed HMI, material scanning via barcode, photos for quality checks, digital signature, and reporting of deviations. The UI is designed for work gloves, short attention spans and mixed lighting, not for a quiet office desk.

PLC/SCADA

Industrial integrations

OPC UA, MQTT, MTConnect, Modbus, Siemens S7 or REST integrations on modern machines for cycle times, running hours, alarms and measurement data. For mixed machine parks, we build a gateway layer that normalises the protocols towards the MES, so the data model doesn't grow with every new machine.

ERP integration

Bidirectional ERP integration

Import production orders from SAP, Microsoft Dynamics, AFAS or Infor LN; feed back actual hours, material consumption and completion notifications. For multi-site organisations, we build a separate adapter per plant so that differences in ERP versions or customisations do not flow through into the MES core.

Compliance

Audit and reporting

Tamper-proof logging of who did what and when, automated reports for GMP, HACCP, ISO 9001 or AS9100, and output in the formats your auditor or regulator expects. Electronic signatures and dual control where regulations require them.

Dashboards

Real-time KPI dashboards

Which order is behind schedule? Which machine causes the most downtime? What is the OEE per shift? How is the FPY developing this month? Dashboards on shop-floor screens, planner workstations and management level, drawn from the same dataset, with no export-to-Excel step in between.

How an MES project runs.

01Introduction→ 02Routing and process analysis→ 03Build in sprints→ 04Rollout and management

Step 01

Introduction

A no-obligation conversation with production, quality and IT. Which process problems we solve, which systems you have, and what your machine park looks like.

Step 02

Routing and process analysis

We model production routings, operations, quality checkpoints and integrations, through workshops with planners, supervisors and operators. The end result is a scope document.

Step 03

Building in sprints

Working modules in two-week sprints. Planners and supervisors test along from the first sprint, operators from the first pilot line. Direct feedback, direct adjustments.

Step 04

Rollout and management

Phased rollout to production: first one line or cell, then scale up. Ongoing management, further development and expansion with new modules or sites.

What we integrate with and build.

For each project we choose what fits your existing landscape. For the broader context of where this MES project fits, see our page on custom software development; for the maintenance layer that often attaches to it, our CMMS expertise.

Industrial & PLC

OPC UAMQTTMTConnectModbusSiemens S7RockwellSCADA integration

ERP & back office

SAPMicrosoft DynamicsAFASInfor LNExactNetSuite

Stack & data

Next.jsNode.jsPythonPostgreSQLTimescaleDBReact NativeKotlinGCP/AWS

Frequently asked questions.

Do you replace Siemens Opcenter, Rockwell FactoryTalk or SAP DM with a custom MES?

For large enterprise organisations that already run a well-functioning Opcenter, FactoryTalk, GE Proficy, Plex or SAP DM/ME, the answer is usually no. Those platforms have been developed over decades and validated across hundreds of plants, and rebuilding them rarely makes sense. We are more often asked in two situations: first, by mid-sized manufacturers for whom such an enterprise licence is disproportionate and the package does not follow their actual routing; second, as a layer alongside such a package, for example a better operator app or a custom andon implementation, while the core stays in the existing system. We advise transparently on which route delivers the most in your situation.

What is the difference between MES, ERP and SCADA?

Three layers, each answering its own question. The ERP plans and administers: which orders are due when, what material we have, what capacity is available, what it all cost. SCADA and PLCs control the machines themselves: valves, motors, sensors and alarms, at millisecond resolution. The MES sits in between and executes: which order is running on which machine, with which operator, using which material batch, at what quality, and it feeds the completed production back to the ERP. A healthy factory keeps all three layers clearly separated, with well-defined integrations and no overlap.

How do you handle PLC and SCADA integration?

We connect modern equipment via OPC UA, MQTT and MTConnect where machines support them; for older installations via Modbus TCP, Siemens S7, Rockwell EtherNet/IP or serial connections through an industrial gateway. For a mixed machine park, we build a gateway layer that normalises the protocols into a single internal API towards the MES, so the data model doesn't grow with every new machine. Cycle time, running hours, downtime, alarms and measurement data arrive in a standardised form, ready to be linked to production orders, quality and OEE reporting.

How do you integrate the MES with our ERP, such as SAP, Dynamics or AFAS?

Bidirectionally, with clear contracts. Production orders, BOMs and planning come in from the ERP; booked hours, material consumption, completion confirmations and quality data flow back. For SAP we integrate via BAPI, OData or S/4HANA REST depending on the version; Microsoft Dynamics via Common Data Service or the Business Central API; AFAS via Profit connectors; Infor LN via ION or Connect; and Exact via the Exact Online API. For multi-site groups, we build a separate adapter per factory so local customisations don't leak into the MES core.

Do you also do predictive maintenance on the machines?

Not as the core of the MES. Predictive maintenance belongs in the maintenance layer rather than the production execution layer. But the two are closely linked: a MES knows when a machine is running, how many cycles it has completed and which alarms have fired, and that data is exactly what a maintenance system needs. We usually build this as an integration with our CMMS layer, so a condition deviation or a running-hours trigger automatically generates a work order in the maintenance system, without planners having to switch between screens.

Does the operator app also work on a fixed HMI, or only on a tablet?

Both, and often mixed within the same factory. We usually build the operator interface as a progressive web app, so the same codebase runs on a fixed HMI at a machine, an industrial tablet at a cell, or a handheld for material scanning. The UI adapts to screen size and input method, but the logic and data model stay identical. For very specific hardware, such as barcode scanners, RFID readers and label printers, we build native integrations where they add real value.

What determines the cost of such an MES project?

Scope (which modules: only dispatch and OEE, or also andon, quality, traceability and multi-site), depth of integration (how many ERPs, how many PLC protocols, how many machines), number of operators and the complexity of your routings. A bounded operator app with OEE on one line is a very different project from a group-wide MES overlay across three factories with separate ERPs. After the scope document, we give you an honest estimate. We don't publish a price list upfront, because without your context any figure would be a guess.

Do you work together with our internal IT team and existing automation partner?

Almost always. A MES project almost certainly touches your existing systems: ERP, PLC stack, SCADA, sometimes a legacy MES of which we take over parts or whose operator layer we replace while the rest stays in place. We work transparently with your IT team and, where needed, with your OT supplier or system integrator. Clear API contracts, documented integrations and an incident runbook are standard. Code, infrastructure-as-code and knowledge stay with you, so you never become dependent on a single agency.

Talk to us about your MES project.

A free, no-obligation half-hour introductory call. We listen to your production process, your machine park, your compliance requirements and your current systems, and we give you direction you can act on, even if it turns out a standard package is the best route.

Production records are often also your audit evidence. For food producers we build this out as IFS and BRCGS audit documentation, and for steel structures as the FPC file.

Schedule an introductory call Email fabian.vandijk@appfront.nl