Engineering change propagation
This is an example architecture, not a client engagement. The operation is composite and the names are generic.
Context
A composite Solar + BESS EPC project where engineering, procurement, project controls, construction and commissioning each hold part of the project's state in a different system.
Operational constraint
The change is approved once, but each function starts acting on the new reality at a different time. Nobody is wrong; the architecture has no defined propagation path.
Design change approvedDecides: Engineering lead
| Function | State it is left in | Decides | System of record | Finds out |
|---|---|---|---|---|
| Engineering | State it is left in:Revision issued | Decides:Engineering lead | System of record:Document control | Finds out:Immediately |
| Procurement | State it is left in:Purchase order still on the old revision | Decides:Nobody defined | System of record:ERP | Finds out:When someone tells them |
| Project controls | State it is left in:Forecast still on the superseded scope | Decides:Project controls | System of record:Cost tool | Finds out:At the next reporting cycle |
| Construction | State it is left in:Building to a superseded drawing | Decides:Site lead | System of record:Field copy | Finds out:When the drawing reaches site |
| Commissioning | State it is left in:Test plan not updated | Decides:Commissioning lead | System of record:Test plan | Finds out:At handover, often |
A dashed marker means the handoff has no defined owner and depends on a person carrying the context.
How to read it
- Two handoffs have no owner at all. They work because an experienced person remembers them.
- Four systems each hold a version of the project. None of them is wrong on its own terms.
- The cost of the change is not what it costs to redraw. It is what gets built, bought and tested against the old revision in the meantime.
- The fix is rarely a new system. It is a defined propagation path, an owner per state, and a record boundary that says which system is authoritative for what.