Seam
L3 ↔ L4 — MES to ERP
Batch and material data, order confirmation, consumption postings, genealogy. The interface defined before the integrator starts: which system owns which object, what is confirmed, and what happens when a message fails overnight. This seam is a frequent source of overrun in integration projects.
Seam
L2 ↔ L3 — batch engine to MES
Recipe and phase structure, parameter download, results and exceptions returning. Designed properly, a new product becomes a recipe change; designed without that structure, it becomes an automation project each time.
Seam
L1 ↔ L2 — control to supervision
Tag design, alarm rationalisation, acquisition rates, and what reaches the historian in a form that can still be queried a year later.
ISA-88
Physical and procedural models
Process cell, unit, equipment module, control module on one side; procedure, unit procedure, operation, phase on the other. Most recipe difficulties share a root cause: procedural logic written into equipment, or equipment assumptions written into recipes.
ISA-88
Recipe hierarchy
General, site, master and control recipes, with a clear owner for each. Getting the master recipe boundary right is what keeps validation effort proportionate as the portfolio grows.
- Master recipe
- Control recipe
Cloud
Cloud alongside the plant
Analytics, historian tiers, MES modules and AI services increasingly sit in Azure or AWS while control stays on site. That hybrid introduces a new boundary — data leaving the qualified estate. We design the flow, the segmentation and the supplier position as one problem rather than three.
- Azure / AWS
- Hybrid
- Data residency
CSV
Validated as one architecture
Five systems validated in isolation leave the interfaces untested, which is precisely where inspectors look. We define the validated boundary across layers, test the data path end to end, and write traceability that follows the record rather than the purchase order.
DI
Data integrity across layers
ALCOA+ applied to a record assembled from four systems: consistent time synchronisation, one user identity model, audit trail coverage that does not stop at a layer boundary, and a defined answer to where the raw data lives.
- ALCOA+
- Time sync
- Audit trail
Run
Keeping it true over time
Architectures drift: an interface is patched, a tag is added, a cloud service updates. Periodic review designed around the data path rather than around individual systems is what keeps the picture accurate between inspections.
- Periodic review
- Change control