This is what we call the common place your systems meet. Below: what that means in practice, how it is built and when you do not need it.
single layer
The common place your systems meet: POS, stock, mail, bank and accounting stop being separate systems.
It is a common place through which your systems data is available in one shape. The till, stock, mail, bank and accounting keep working as they did, but stop being separate worlds: a question is asked once and does not depend on which program holds the answer.
What it is not matters just as much. The single layer is not a new system replacing yours, and not a store of copies of your data. The data stays where it was created.
So that a repeating decision is taken on data rather than from memory. While there are several systems and no links between them, every question - what do we actually pay this supplier, why did the cost of goods move - turns into a manual reconciliation done by a person in their spare time.
The layer removes that manual work, not the programs. So its effect is counted in hours of reconciliation and in how fast an answer arrives, not in how much software was installed.
From three parts. Connections to the systems, each giving what it is able to give. Shared reference data - suppliers, items, locations: without it two systems never agree. And an access point the layer is reached through by people, reports and agents; for us that is the MCP router.
It is not built all at once. The first thing connected is where a manual reconciliation repeats every week, and the layer then grows one source at a time.
A warehouse gathers copies of the data in itself and lives by its own export schedule. The single layer keeps no copies: it reaches into the systems and returns what is in them now.
Hence the difference in cost of ownership. A warehouse needs somebody to keep the exports alive and to watch them drift from the source. The layer needs somebody who owns the reference data, which is work of a different size.
When there are one or two systems and the manual reconciliation takes half an hour a week. Then the layer solves a problem you do not have.
And when the process still changes every month. The layer fixes how the company works today; if today keeps moving, let the order settle first.
No. The layer is built on top of what exists: the team keeps working where it worked. Replacing a system makes sense when the system itself is the obstacle - when it cannot hand its data out at all, for instance.
Where it lived before, in your systems. The layer does not create a second copy, it gives shared access to them. The architecture and the description of the connections stay with you.
It depends on whether the system can hand data out. Where there is documented access it is days; where the export is done by hand, that question is settled first. We name timelines after looking at your set of systems, not before.
No, it is the opposite approach. Point-to-point links grow in number and break on every update. The layer gives one point that both the systems and whatever reads them connect to.